Linux vulnerabilities

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix KASAN slab-out-of-bounds in cachefiles_set_volume_xattr Use the actual length of volume coherency data when setting the xattr to avoid the following KASAN report. BUG: KASAN: slab-out-of-bounds in cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] Write of size 4 at addr ffff888101e02af4 by task kworker/6:0/1347 CPU: 6 PID: 1347 Comm: kworker/6:0 Kdump: loaded Not tainted 5.18.0-rc1-nfs-fscache-netfs+ #13 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-4.fc34 04/01/2014 Workqueue: events fscache_create_volume_work [fscache] Call Trace: <TASK> dump_stack_lvl+0x45/0x5a print_report.cold+0x5e/0x5db ? __lock_text_start+0x8/0x8 ? cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] kasan_report+0xab/0x120 ? cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] kasan_check_range+0xf5/0x1d0 memcpy+0x39/0x60 cachefiles_set_volume_xattr+0xa0/0x350 [cachefiles] cachefiles_acquire_volume+0x2be/0x500 [cachefiles] ? __cachefiles_free_volume+0x90/0x90 [cachefiles] fscache_create_volume_work+0x68/0x160 [fscache] process_one_work+0x3b7/0x6a0 worker_thread+0x2c4/0x650 ? process_one_work+0x6a0/0x6a0 kthread+0x16c/0x1a0 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 </TASK> Allocated by task 1347: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 cachefiles_set_volume_xattr+0x76/0x350 [cachefiles] cachefiles_acquire_volume+0x2be/0x500 [cachefiles] fscache_create_volume_work+0x68/0x160 [fscache] process_one_work+0x3b7/0x6a0 worker_thread+0x2c4/0x650 kthread+0x16c/0x1a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff888101e02af0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 4 bytes inside of 8-byte region [ffff888101e02af0, ffff888101e02af8) The buggy address belongs to the physical page: page:00000000a2292d70 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101e02 flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0000200 0000000000000000 dead000000000001 ffff888100042280 raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888101e02980: fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc ffff888101e02a00: 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 >ffff888101e02a80: fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 04 fc ^ ffff888101e02b00: fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc ffff888101e02b80: fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc ==================================================================

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: stmmac: fix altr_tse_pcs function when using a fixed-link When using a fixed-link, the altr_tse_pcs driver crashes due to null-pointer dereference as no phy_device is provided to tse_pcs_fix_mac_speed function. Fix this by adding a check for phy_dev before calling the tse_pcs_fix_mac_speed() function. Also clean up the tse_pcs_fix_mac_speed function a bit. There is no need to check for splitter_base and sgmii_adapter_base because the driver will fail if these 2 variables are not derived from the device tree.

In the Linux kernel, the following vulnerability has been resolved: net/smc: Fix NULL pointer dereference in smc_pnet_find_ib() dev_name() was called with dev.parent as argument but without to NULL-check it before. Solve this by checking the pointer before the call to dev_name().

In the Linux kernel, the following vulnerability has been resolved: cifs: potential buffer overflow in handling symlinks Smatch printed a warning: arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error: __memcpy() 'dctx->buf' too small (16 vs u32max) It's caused because Smatch marks 'link_len' as untrusted since it comes from sscanf(). Add a check to ensure that 'link_len' is not larger than the size of the 'link_str' buffer.

In the Linux kernel, the following vulnerability has been resolved: block: null_blk: end timed out poll request When poll request is timed out, it is removed from the poll list, but not completed, so the request is leaked, and never get chance to complete. Fix the issue by ending it in timeout handler.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Check for potential null return of kmalloc_array() As the kmalloc_array() may return null, the 'event_waiters[i].wait' would lead to null-pointer dereference. Therefore, it is better to check the return value of kmalloc_array() to avoid this confusion.

In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests hv_panic_page might contain guest-sensitive information, do not dump it over to Hyper-V by default in isolated guests. While at it, update some comments in hyperv_{panic,die}_event().

In the Linux kernel, the following vulnerability has been resolved: mm: fix unexpected zeroed page mapping with zram swap Two processes under CLONE_VM cloning, user process can be corrupted by seeing zeroed page unexpectedly. CPU A CPU B do_swap_page do_swap_page SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path swap_readpage valid data swap_slot_free_notify delete zram entry swap_readpage zeroed(invalid) data pte_lock map the *zero data* to userspace pte_unlock pte_lock if (!pte_same) goto out_nomap; pte_unlock return and next refault will read zeroed data The swap_slot_free_notify is bogus for CLONE_VM case since it doesn't increase the refcount of swap slot at copy_mm so it couldn't catch up whether it's safe or not to discard data from backing device. In the case, only the lock it could rely on to synchronize swap slot freeing is page table lock. Thus, this patch gets rid of the swap_slot_free_notify function. With this patch, CPU A will see correct data. CPU A CPU B do_swap_page do_swap_page SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path swap_readpage original data pte_lock map the original data swap_free swap_range_free bd_disk->fops->swap_slot_free_notify swap_readpage read zeroed data pte_unlock pte_lock if (!pte_same) goto out_nomap; pte_unlock return on next refault will see mapped data by CPU B The concern of the patch would increase memory consumption since it could keep wasted memory with compressed form in zram as well as uncompressed form in address space. However, most of cases of zram uses no readahead and do_swap_page is followed by swap_free so it will free the compressed form from in zram quickly.

In the Linux kernel, the following vulnerability has been resolved: net: usb: aqc111: Fix out-of-bounds accesses in RX fixup aqc111_rx_fixup() contains several out-of-bounds accesses that can be triggered by a malicious (or defective) USB device, in particular: - The metadata array (desc_offset..desc_offset+2*pkt_count) can be out of bounds, causing OOB reads and (on big-endian systems) OOB endianness flips. - A packet can overlap the metadata array, causing a later OOB endianness flip to corrupt data used by a cloned SKB that has already been handed off into the network stack. - A packet SKB can be constructed whose tail is far beyond its end, causing out-of-bounds heap data to be considered part of the SKB's data. Found doing variant analysis. Tested it with another driver (ax88179_178a), since I don't have a aqc111 device to test it, but the code looks very similar.

In the Linux kernel, the following vulnerability has been resolved: memory: renesas-rpc-if: fix platform-device leak in error path Make sure to free the flash platform device in the event that registration fails during probe.

In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix panic when growing a memfd_secret When one tries to grow an existing memfd_secret with ftruncate, one gets a panic [1]. For example, doing the following reliably induces the panic: fd = memfd_secret(); ftruncate(fd, 10); ptr = mmap(NULL, 10, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); strcpy(ptr, "123456789"); munmap(ptr, 10); ftruncate(fd, 20); The basic reason for this is, when we grow with ftruncate, we call down into simple_setattr, and then truncate_inode_pages_range, and eventually we try to zero part of the memory. The normal truncation code does this via the direct map (i.e., it calls page_address() and hands that to memset()). For memfd_secret though, we specifically don't map our pages via the direct map (i.e. we call set_direct_map_invalid_noflush() on every fault). So the address returned by page_address() isn't useful, and when we try to memset() with it we panic. This patch avoids the panic by implementing a custom setattr for memfd_secret, which detects resizes specifically (setting the size for the first time works just fine, since there are no existing pages to try to zero), and rejects them with EINVAL. One could argue growing should be supported, but I think that will require a significantly more lengthy change. So, I propose a minimal fix for the benefit of stable kernels, and then perhaps to extend memfd_secret to support growing in a separate patch. [1]: BUG: unable to handle page fault for address: ffffa0a889277028 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD afa01067 P4D afa01067 PUD 83f909067 PMD 83f8bf067 PTE 800ffffef6d88060 Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI CPU: 0 PID: 281 Comm: repro Not tainted 5.17.0-dbg-DEV #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:memset_erms+0x9/0x10 Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 RSP: 0018:ffffb932c09afbf0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffda63c4249dc0 RCX: 0000000000000fd8 RDX: 0000000000000fd8 RSI: 0000000000000000 RDI: ffffa0a889277028 RBP: ffffb932c09afc00 R08: 0000000000001000 R09: ffffa0a889277028 R10: 0000000000020023 R11: 0000000000000000 R12: ffffda63c4249dc0 R13: ffffa0a890d70d98 R14: 0000000000000028 R15: 0000000000000fd8 FS: 00007f7294899580(0000) GS:ffffa0af9bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa0a889277028 CR3: 0000000107ef6006 CR4: 0000000000370ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? zero_user_segments+0x82/0x190 truncate_inode_partial_folio+0xd4/0x2a0 truncate_inode_pages_range+0x380/0x830 truncate_setsize+0x63/0x80 simple_setattr+0x37/0x60 notify_change+0x3d8/0x4d0 do_sys_ftruncate+0x162/0x1d0 __x64_sys_ftruncate+0x1c/0x20 do_syscall_64+0x44/0xa0 entry_SYSCALL_64_after_hwframe+0x44/0xae Modules linked in: xhci_pci xhci_hcd virtio_net net_failover failover virtio_blk virtio_balloon uhci_hcd ohci_pci ohci_hcd evdev ehci_pci ehci_hcd 9pnet_virtio 9p netfs 9pnet CR2: ffffa0a889277028 [lkp@intel.com: secretmem_iops can be static] [axelrasmussen@google.com: return EINVAL]

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix panic when forwarding a pkt with no in6 dev kongweibin reported a kernel panic in ip6_forward() when input interface has no in6 dev associated. The following tc commands were used to reproduce this panic: tc qdisc del dev vxlan100 root tc qdisc add dev vxlan100 root netem corrupt 5%

In the Linux kernel, the following vulnerability has been resolved: i2c: dev: check return value when calling dev_set_name() If dev_set_name() fails, the dev_name() is null, check the return value of dev_set_name() to avoid the null-ptr-deref.

In the Linux kernel, the following vulnerability has been resolved: dm integrity: fix memory corruption when tag_size is less than digest size It is possible to set up dm-integrity in such a way that the "tag_size" parameter is less than the actual digest size. In this situation, a part of the digest beyond tag_size is ignored. In this case, dm-integrity would write beyond the end of the ic->recalc_tags array and corrupt memory. The corruption happened in integrity_recalc->integrity_sector_checksum->crypto_shash_final. Fix this corruption by increasing the tags array so that it has enough padding at the end to accomodate the loop in integrity_recalc() being able to write a full digest size for the last member of the tags array.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix a potential gpu_metrics_table memory leak Memory is allocated for gpu_metrics_table in renoir_init_smc_tables(), but not freed in int smu_v12_0_fini_smc_tables(). Free it!

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix some memory leaks in an error handling path of 'log_replay()' All error handling paths lead to 'out' where many resources are freed. Do it as well here instead of a direct return, otherwise 'log', 'ra' and 'log->one_page_buf' (at least) will leak.

In the Linux kernel, the following vulnerability has been resolved: drm/plane: Move range check for format_count earlier While the check for format_count > 64 in __drm_universal_plane_init() shouldn't be hit (it's a WARN_ON), in its current position it will then leak the plane->format_types array and fail to call drm_mode_object_unregister() leaking the modeset identifier. Move it to the start of the function to avoid allocating those resources in the first place.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/pm: fix a potential gpu_metrics_table memory leak Memory is allocated for gpu_metrics_table in renoir_init_smc_tables(), but not freed in int smu_v12_0_fini_smc_tables(). Free it!

In the Linux kernel, the following vulnerability has been resolved: drm/virtio: Ensure that objs is not NULL in virtio_gpu_array_put_free() If virtio_gpu_object_shmem_init() fails (e.g. due to fault injection, as it happened in the bug report by syzbot), virtio_gpu_array_put_free() could be called with objs equal to NULL. Ensure that objs is not NULL in virtio_gpu_array_put_free(), or otherwise return from the function.

In the Linux kernel, the following vulnerability has been resolved: media: venus: vdec: fixed possible memory leak issue The venus_helper_alloc_dpb_bufs() implementation allows an early return on an error path when checking the id from ida_alloc_min() which would not release the earlier buffer allocation. Move the direct kfree() from the error checking of dma_alloc_attrs() to the common fail path to ensure that allocations are released on all error paths in this function. Addresses-Coverity: 1494120 ("Resource leak")

In the Linux kernel, the following vulnerability has been resolved: samples/landlock: Fix path_list memory leak Clang static analysis reports this error sandboxer.c:134:8: warning: Potential leak of memory pointed to by 'path_list' ret = 0; ^ path_list is allocated in parse_path() but never freed.

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: smscufx: Fix null-ptr-deref in ufx_usb_probe() I got a null-ptr-deref report: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... RIP: 0010:fb_destroy_modelist+0x38/0x100 ... Call Trace: ufx_usb_probe.cold+0x2b5/0xac1 [smscufx] usb_probe_interface+0x1aa/0x3c0 [usbcore] really_probe+0x167/0x460 ... ret_from_fork+0x1f/0x30 If fb_alloc_cmap() fails in ufx_usb_probe(), fb_destroy_modelist() will be called to destroy modelist in the error handling path. But modelist has not been initialized yet, so it will result in null-ptr-deref. Initialize modelist before calling fb_alloc_cmap() to fix this bug.

In the Linux kernel, the following vulnerability has been resolved: soc: qcom: rpmpd: Check for null return of devm_kcalloc Because of the possible failure of the allocation, data->domains might be NULL pointer and will cause the dereference of the NULL pointer later. Therefore, it might be better to check it and directly return -ENOMEM without releasing data manually if fails, because the comment of the devm_kmalloc() says "Memory allocated with this function is automatically freed on driver detach.".

In the Linux kernel, the following vulnerability has been resolved: ASoC: soc-compress: prevent the potentially use of null pointer There is one call trace that snd_soc_register_card() ->snd_soc_bind_card()->soc_init_pcm_runtime() ->snd_soc_dai_compress_new()->snd_soc_new_compress(). In the trace the 'codec_dai' transfers from card->dai_link, and we can see from the snd_soc_add_pcm_runtime() in snd_soc_bind_card() that, if value of card->dai_link->num_codecs is 0, then 'codec_dai' could be null pointer caused by index out of bound in 'asoc_rtd_to_codec(rtd, 0)'. And snd_soc_register_card() is called by various platforms. Therefore, it is better to add the check in the case of misusing. And because 'cpu_dai' has already checked in soc_init_pcm_runtime(), there is no need to check again. Adding the check as follow, then if 'codec_dai' is null, snd_soc_new_compress() will not pass through the check 'if (playback + capture != 1)', avoiding the leftover use of 'codec_dai'.

In the Linux kernel, the following vulnerability has been resolved: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().

In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Fix a memory leak in 'host1x_remove()' Add a missing 'host1x_channel_list_free()' call in the remove function, as already done in the error handling path of the probe function.

In the Linux kernel, the following vulnerability has been resolved: clk: qcom: ipq8074: fix PCI-E clock oops Fix PCI-E clock related kernel oops that are caused by a missing clock parent. pcie0_rchng_clk_src has num_parents set to 2 but only one parent is actually set via parent_hws, it should also have "XO" defined. This will cause the kernel to panic on a NULL pointer in clk_core_get_parent_by_index(). So, to fix this utilize clk_parent_data to provide gcc_xo_gpll0 parent data. Since there is already an existing static const char * const gcc_xo_gpll0[] used to provide the same parents via parent_names convert those users to clk_parent_data as well. Without this earlycon is needed to even catch the OOPS as it will reset the board before serial is initialized with the following: [ 0.232279] Unable to handle kernel paging request at virtual address 0000a00000000000 [ 0.232322] Mem abort info: [ 0.239094] ESR = 0x96000004 [ 0.241778] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.244908] SET = 0, FnV = 0 [ 0.250377] EA = 0, S1PTW = 0 [ 0.253236] FSC = 0x04: level 0 translation fault [ 0.256277] Data abort info: [ 0.261141] ISV = 0, ISS = 0x00000004 [ 0.264262] CM = 0, WnR = 0 [ 0.267820] [0000a00000000000] address between user and kernel address ranges [ 0.270954] Internal error: Oops: 96000004 [#1] SMP [ 0.278067] Modules linked in: [ 0.282751] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.15.10 #0 [ 0.285882] Hardware name: Xiaomi AX3600 (DT) [ 0.292043] pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.296299] pc : clk_core_get_parent_by_index+0x68/0xec [ 0.303067] lr : __clk_register+0x1d8/0x820 [ 0.308273] sp : ffffffc01111b7d0 [ 0.312438] x29: ffffffc01111b7d0 x28: 0000000000000000 x27: 0000000000000040 [ 0.315919] x26: 0000000000000002 x25: 0000000000000000 x24: ffffff8000308800 [ 0.323037] x23: ffffff8000308850 x22: ffffff8000308880 x21: ffffff8000308828 [ 0.330155] x20: 0000000000000028 x19: ffffff8000309700 x18: 0000000000000020 [ 0.337272] x17: 000000005cc86990 x16: 0000000000000004 x15: ffffff80001d9d0a [ 0.344391] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000006 [ 0.351508] x11: 0000000000000003 x10: 0101010101010101 x9 : 0000000000000000 [ 0.358626] x8 : 7f7f7f7f7f7f7f7f x7 : 6468626f5e626266 x6 : 17000a3a403c1b06 [ 0.365744] x5 : 061b3c403a0a0017 x4 : 0000000000000000 x3 : 0000000000000001 [ 0.372863] x2 : 0000a00000000000 x1 : 0000000000000001 x0 : ffffff8000309700 [ 0.379982] Call trace: [ 0.387091] clk_core_get_parent_by_index+0x68/0xec [ 0.389351] __clk_register+0x1d8/0x820 [ 0.394210] devm_clk_hw_register+0x5c/0xe0 [ 0.398030] devm_clk_register_regmap+0x44/0x8c [ 0.402198] qcom_cc_really_probe+0x17c/0x1d0 [ 0.406711] qcom_cc_probe+0x34/0x44 [ 0.411224] gcc_ipq8074_probe+0x18/0x30 [ 0.414869] platform_probe+0x68/0xe0 [ 0.418776] really_probe.part.0+0x9c/0x30c [ 0.422336] __driver_probe_device+0x98/0x144 [ 0.426329] driver_probe_device+0x44/0x11c [ 0.430842] __device_attach_driver+0xb4/0x120 [ 0.434836] bus_for_each_drv+0x68/0xb0 [ 0.439349] __device_attach+0xb0/0x170 [ 0.443081] device_initial_probe+0x14/0x20 [ 0.446901] bus_probe_device+0x9c/0xa4 [ 0.451067] device_add+0x35c/0x834 [ 0.454886] of_device_add+0x54/0x64 [ 0.458360] of_platform_device_create_pdata+0xc0/0x100 [ 0.462181] of_platform_bus_create+0x114/0x370 [ 0.467128] of_platform_bus_create+0x15c/0x370 [ 0.471641] of_platform_populate+0x50/0xcc [ 0.476155] of_platform_default_populate_init+0xa8/0xc8 [ 0.480324] do_one_initcall+0x50/0x1b0 [ 0.485877] kernel_init_freeable+0x234/0x29c [ 0.489436] kernel_init+0x24/0x120 [ 0.493948] ret_from_fork+0x10/0x20 [ 0.497253] Code: d50323bf d65f03c0 f94002a2 b4000302 (f9400042) [ 0.501079] ---[ end trace 4ca7e1129da2abce ]---

In the Linux kernel, the following vulnerability has been resolved: media: staging: media: zoran: calculate the right buffer number for zoran_reap_stat_com On the case tmp_dcim=1, the index of buffer is miscalculated. This generate a NULL pointer dereference later. So let's fix the calcul and add a check to prevent this to reappear.

In the Linux kernel, the following vulnerability has been resolved: media: staging: media: zoran: move videodev alloc Move some code out of zr36057_init() and create new functions for handling zr->video_dev. This permit to ease code reading and fix a zr->video_dev memory leak.

In the Linux kernel, the following vulnerability has been resolved: media: ir_toy: free before error exiting Fix leak in error path.

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: nvidiafb: Use strscpy() to prevent buffer overflow Coverity complains of a possible buffer overflow. However, given the 'static' scope of nvidia_setup_i2c_bus() it looks like that can't happen after examiniing the call sites. CID 19036 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW) 1. fixed_size_dest: You might overrun the 48-character fixed-size string chan->adapter.name by copying name without checking the length. 2. parameter_as_source: Note: This defect has an elevated risk because the source argument is a parameter of the current function. 89 strcpy(chan->adapter.name, name); Fix this warning by using strscpy() which will silence the warning and prevent any future buffer overflows should the names used to identify the channel become much longer.

In the Linux kernel, the following vulnerability has been resolved: video: fbdev: cirrusfb: check pixclock to avoid divide by zero Do a sanity check on pixclock value to avoid divide by zero. If the pixclock value is zero, the cirrusfb driver will round up pixclock to get the derived frequency as close to maxclock as possible. Syzkaller reported a divide error in cirrusfb_check_pixclock. divide error: 0000 [#1] SMP KASAN PTI CPU: 0 PID: 14938 Comm: cirrusfb_test Not tainted 5.15.0-rc6 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2 RIP: 0010:cirrusfb_check_var+0x6f1/0x1260 Call Trace: fb_set_var+0x398/0xf90 do_fb_ioctl+0x4b8/0x6f0 fb_ioctl+0xeb/0x130 __x64_sys_ioctl+0x19d/0x220 do_syscall_64+0x3a/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: powerpc/kasan: Fix early region not updated correctly The shadow's page table is not updated when PTE_RPN_SHIFT is 24 and PAGE_SHIFT is 12. It not only causes false positives but also false negative as shown the following text. Fix it by bringing the logic of kasan_early_shadow_page_entry here. 1. False Positive: ================================================================== BUG: KASAN: vmalloc-out-of-bounds in pcpu_alloc+0x508/0xa50 Write of size 16 at addr f57f3be0 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-12267-gdebe436e77c7 #1 Call Trace: [c80d1c20] [c07fe7b8] dump_stack_lvl+0x4c/0x6c (unreliable) [c80d1c40] [c02ff668] print_address_description.constprop.0+0x88/0x300 [c80d1c70] [c02ff45c] kasan_report+0x1ec/0x200 [c80d1cb0] [c0300b20] kasan_check_range+0x160/0x2f0 [c80d1cc0] [c03018a4] memset+0x34/0x90 [c80d1ce0] [c0280108] pcpu_alloc+0x508/0xa50 [c80d1d40] [c02fd7bc] __kmem_cache_create+0xfc/0x570 [c80d1d70] [c0283d64] kmem_cache_create_usercopy+0x274/0x3e0 [c80d1db0] [c2036580] init_sd+0xc4/0x1d0 [c80d1de0] [c00044a0] do_one_initcall+0xc0/0x33c [c80d1eb0] [c2001624] kernel_init_freeable+0x2c8/0x384 [c80d1ef0] [c0004b14] kernel_init+0x24/0x170 [c80d1f10] [c001b26c] ret_from_kernel_thread+0x5c/0x64 Memory state around the buggy address: f57f3a80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f57f3b00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >f57f3b80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ f57f3c00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f57f3c80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== 2. False Negative (with KASAN tests): ================================================================== Before fix: ok 45 - kmalloc_double_kzfree # vmalloc_oob: EXPECTATION FAILED at lib/test_kasan.c:1039 KASAN failure expected in "((volatile char *)area)[3100]", but none occurred not ok 46 - vmalloc_oob not ok 1 - kasan ================================================================== After fix: ok 1 - kasan

In the Linux kernel, the following vulnerability has been resolved: ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0).

In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes).

In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock() Function ubifs_wbuf_write_nolock() may access buf out of bounds in following process: ubifs_wbuf_write_nolock(): aligned_len = ALIGN(len, 8); // Assume len = 4089, aligned_len = 4096 if (aligned_len <= wbuf->avail) ... // Not satisfy if (wbuf->used) { ubifs_leb_write() // Fill some data in avail wbuf len -= wbuf->avail; // len is still not 8-bytes aligned aligned_len -= wbuf->avail; } n = aligned_len >> c->max_write_shift; if (n) { n <<= c->max_write_shift; err = ubifs_leb_write(c, wbuf->lnum, buf + written, wbuf->offs, n); // n > len, read out of bounds less than 8(n-len) bytes } , which can be catched by KASAN: ========================================================= BUG: KASAN: slab-out-of-bounds in ecc_sw_hamming_calculate+0x1dc/0x7d0 Read of size 4 at addr ffff888105594ff8 by task kworker/u8:4/128 Workqueue: writeback wb_workfn (flush-ubifs_0_0) Call Trace: kasan_report.cold+0x81/0x165 nand_write_page_swecc+0xa9/0x160 ubifs_leb_write+0xf2/0x1b0 [ubifs] ubifs_wbuf_write_nolock+0x421/0x12c0 [ubifs] write_head+0xdc/0x1c0 [ubifs] ubifs_jnl_write_inode+0x627/0x960 [ubifs] wb_workfn+0x8af/0xb80 Function ubifs_wbuf_write_nolock() accepts that parameter 'len' is not 8 bytes aligned, the 'len' represents the true length of buf (which is allocated in 'ubifs_jnl_xxx', eg. ubifs_jnl_write_inode), so ubifs_wbuf_write_nolock() must handle the length read from 'buf' carefully to write leb safely. Fetch a reproducer in [Link].

In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix to add refcount once page is set private MM defined the rule [1] very clearly that once page was set with PG_private flag, we should increment the refcount in that page, also main flows like pageout(), migrate_page() will assume there is one additional page reference count if page_has_private() returns true. Otherwise, we may get a BUG in page migration: page:0000000080d05b9d refcount:-1 mapcount:0 mapping:000000005f4d82a8 index:0xe2 pfn:0x14c12 aops:ubifs_file_address_operations [ubifs] ino:8f1 dentry name:"f30e" flags: 0x1fffff80002405(locked|uptodate|owner_priv_1|private|node=0| zone=1|lastcpupid=0x1fffff) page dumped because: VM_BUG_ON_PAGE(page_count(page) != 0) ------------[ cut here ]------------ kernel BUG at include/linux/page_ref.h:184! invalid opcode: 0000 [#1] SMP CPU: 3 PID: 38 Comm: kcompactd0 Not tainted 5.15.0-rc5 RIP: 0010:migrate_page_move_mapping+0xac3/0xe70 Call Trace: ubifs_migrate_page+0x22/0xc0 [ubifs] move_to_new_page+0xb4/0x600 migrate_pages+0x1523/0x1cc0 compact_zone+0x8c5/0x14b0 kcompactd+0x2bc/0x560 kthread+0x18c/0x1e0 ret_from_fork+0x1f/0x30 Before the time, we should make clean a concept, what does refcount means in page gotten from grab_cache_page_write_begin(). There are 2 situations: Situation 1: refcount is 3, page is created by __page_cache_alloc. TYPE_A - the write process is using this page TYPE_B - page is assigned to one certain mapping by calling __add_to_page_cache_locked() TYPE_C - page is added into pagevec list corresponding current cpu by calling lru_cache_add() Situation 2: refcount is 2, page is gotten from the mapping's tree TYPE_B - page has been assigned to one certain mapping TYPE_A - the write process is using this page (by calling page_cache_get_speculative()) Filesystem releases one refcount by calling put_page() in xxx_write_end(), the released refcount corresponds to TYPE_A (write task is using it). If there are any processes using a page, page migration process will skip the page by judging whether expected_page_refs() equals to page refcount. The BUG is caused by following process: PA(cpu 0) kcompactd(cpu 1) compact_zone ubifs_write_begin page_a = grab_cache_page_write_begin add_to_page_cache_lru lru_cache_add pagevec_add // put page into cpu 0's pagevec (refcnf = 3, for page creation process) ubifs_write_end SetPagePrivate(page_a) // doesn't increase page count ! unlock_page(page_a) put_page(page_a) // refcnt = 2 [...] PB(cpu 0) filemap_read filemap_get_pages add_to_page_cache_lru lru_cache_add __pagevec_lru_add // traverse all pages in cpu 0's pagevec __pagevec_lru_add_fn SetPageLRU(page_a) isolate_migratepages isolate_migratepages_block get_page_unless_zero(page_a) // refcnt = 3 list_add(page_a, from_list) migrate_pages(from_list) __unmap_and_move move_to_new_page ubifs_migrate_page(page_a) migrate_page_move_mapping expected_page_refs get 3 (migration[1] + mapping[1] + private[1]) release_pages put_page_testzero(page_a) // refcnt = 3 page_ref_freeze // refcnt = 0 page_ref_dec_and_test(0 - 1 = -1) page_ref_unfreeze VM_BUG_ON_PAGE(-1 != 0, page) UBIFS doesn't increase the page refcount after setting private flag, which leads to page migration task believes the page is not used by any other processes, so the page is migrated. This causes concurrent accessing on page refcount between put_page() called by other process(eg. read process calls lru_cache_add) and page_ref_unfreeze() called by mi ---truncated---

In the Linux kernel, the following vulnerability has been resolved: ath5k: fix OOB in ath5k_eeprom_read_pcal_info_5111 The bug was found during fuzzing. Stacktrace locates it in ath5k_eeprom_convert_pcal_info_5111. When none of the curve is selected in the loop, idx can go up to AR5K_EEPROM_N_PD_CURVES. The line makes pd out of bound. pd = &chinfo[pier].pd_curves[idx]; There are many OOB writes using pd later in the code. So I added a sanity check for idx. Checks for other loops involving AR5K_EEPROM_N_PD_CURVES are not needed as the loop index is not used outside the loops. The patch is NOT tested with real device. The following is the fuzzing report BUG: KASAN: slab-out-of-bounds in ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] Write of size 1 at addr ffff8880174a4d60 by task modprobe/214 CPU: 0 PID: 214 Comm: modprobe Not tainted 5.6.0 #1 Call Trace: dump_stack+0x76/0xa0 print_address_description.constprop.0+0x16/0x200 ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] __kasan_report.cold+0x37/0x7c ? ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] kasan_report+0xe/0x20 ath5k_eeprom_read_pcal_info_5111+0x126a/0x1390 [ath5k] ? apic_timer_interrupt+0xa/0x20 ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k] ? ath5k_pci_eeprom_read+0x228/0x3c0 [ath5k] ath5k_eeprom_init+0x2513/0x6290 [ath5k] ? ath5k_eeprom_init_11a_pcal_freq+0xbc0/0xbc0 [ath5k] ? usleep_range+0xb8/0x100 ? apic_timer_interrupt+0xa/0x20 ? ath5k_eeprom_read_pcal_info_2413+0x2f20/0x2f20 [ath5k] ath5k_hw_init+0xb60/0x1970 [ath5k] ath5k_init_ah+0x6fe/0x2530 [ath5k] ? kasprintf+0xa6/0xe0 ? ath5k_stop+0x140/0x140 [ath5k] ? _dev_notice+0xf6/0xf6 ? apic_timer_interrupt+0xa/0x20 ath5k_pci_probe.cold+0x29a/0x3d6 [ath5k] ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k] ? mutex_lock+0x89/0xd0 ? ath5k_pci_eeprom_read+0x3c0/0x3c0 [ath5k] local_pci_probe+0xd3/0x160 pci_device_probe+0x23f/0x3e0 ? pci_device_remove+0x280/0x280 ? pci_device_remove+0x280/0x280 really_probe+0x209/0x5d0

In the Linux kernel, the following vulnerability has been resolved: powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38 ("powerpc/mm: Implement set_memory() routines") included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_page_attr(). To do the operation atomically, we can't use pte modification helpers anymore. Because all platforms have different combination of bits, it is not easy to use those bits directly. But all have the _PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare two sets to know which bits are set or cleared. For instance, by comparing _PAGE_KERNEL_ROX and _PAGE_KERNEL_RO you know which bit gets cleared and which bit get set when changing exec permission.

In the Linux kernel, the following vulnerability has been resolved: ARM: davinci: da850-evm: Avoid NULL pointer dereference With newer versions of GCC, there is a panic in da850_evm_config_emac() when booting multi_v5_defconfig in QEMU under the palmetto-bmc machine: Unable to handle kernel NULL pointer dereference at virtual address 00000020 pgd = (ptrval) [00000020] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.15.0 #1 Hardware name: Generic DT based system PC is at da850_evm_config_emac+0x1c/0x120 LR is at do_one_initcall+0x50/0x1e0 The emac_pdata pointer in soc_info is NULL because davinci_soc_info only gets populated on davinci machines but da850_evm_config_emac() is called on all machines via device_initcall(). Move the rmii_en assignment below the machine check so that it is only dereferenced when running on a supported SoC.

In the Linux kernel, the following vulnerability has been resolved: IORING_OP_READ did not correctly consume the provided buffer list when read i/o returned < 0 (except for -EAGAIN and -EIOCBQUEUED return). This can lead to a potential use-after-free when the completion via io_rw_done runs at separate context.

In the Linux kernel, the following vulnerability has been resolved: usb: cdc-acm: Check control transfer buffer size before access If the first fragment is shorter than struct usb_cdc_notification, we can't calculate an expected_size. Log an error and discard the notification instead of reading lengths from memory outside the received data, which can lead to memory corruption when the expected_size decreases between fragments, causing `expected_size - acm->nb_index` to wrap. This issue has been present since the beginning of git history; however, it only leads to memory corruption since commit ea2583529cd1 ("cdc-acm: reassemble fragmented notifications"). A mitigating factor is that acm_ctrl_irq() can only execute after userspace has opened /dev/ttyACM*; but if ModemManager is running, ModemManager will do that automatically depending on the USB device's vendor/product IDs and its other interfaces.

In the Linux kernel, the following vulnerability has been resolved: netem: Update sch->q.qlen before qdisc_tree_reduce_backlog() qdisc_tree_reduce_backlog() notifies parent qdisc only if child qdisc becomes empty, therefore we need to reduce the backlog of the child qdisc before calling it. Otherwise it would miss the opportunity to call cops->qlen_notify(), in the case of DRR, it resulted in UAF since DRR uses ->qlen_notify() to maintain its active list.

In the Linux kernel, the following vulnerability has been resolved: pfifo_tail_enqueue: Drop new packet when sch->limit == 0 Expected behaviour: In case we reach scheduler's limit, pfifo_tail_enqueue() will drop a packet in scheduler's queue and decrease scheduler's qlen by one. Then, pfifo_tail_enqueue() enqueue new packet and increase scheduler's qlen by one. Finally, pfifo_tail_enqueue() return `NET_XMIT_CN` status code. Weird behaviour: In case we set `sch->limit == 0` and trigger pfifo_tail_enqueue() on a scheduler that has no packet, the 'drop a packet' step will do nothing. This means the scheduler's qlen still has value equal 0. Then, we continue to enqueue new packet and increase scheduler's qlen by one. In summary, we can leverage pfifo_tail_enqueue() to increase qlen by one and return `NET_XMIT_CN` status code. The problem is: Let's say we have two qdiscs: Qdisc_A and Qdisc_B. - Qdisc_A's type must have '->graft()' function to create parent/child relationship. Let's say Qdisc_A's type is `hfsc`. Enqueue packet to this qdisc will trigger `hfsc_enqueue`. - Qdisc_B's type is pfifo_head_drop. Enqueue packet to this qdisc will trigger `pfifo_tail_enqueue`. - Qdisc_B is configured to have `sch->limit == 0`. - Qdisc_A is configured to route the enqueued's packet to Qdisc_B. Enqueue packet through Qdisc_A will lead to: - hfsc_enqueue(Qdisc_A) -> pfifo_tail_enqueue(Qdisc_B) - Qdisc_B->q.qlen += 1 - pfifo_tail_enqueue() return `NET_XMIT_CN` - hfsc_enqueue() check for `NET_XMIT_SUCCESS` and see `NET_XMIT_CN` => hfsc_enqueue() don't increase qlen of Qdisc_A. The whole process lead to a situation where Qdisc_A->q.qlen == 0 and Qdisc_B->q.qlen == 1. Replace 'hfsc' with other type (for example: 'drr') still lead to the same problem. This violate the design where parent's qlen should equal to the sum of its childrens'qlen. Bug impact: This issue can be used for user->kernel privilege escalation when it is reachable.

In the Linux kernel, the following vulnerability has been resolved: net: avoid race between device unregistration and ethnl ops The following trace can be seen if a device is being unregistered while its number of channels are being modified. DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 3 PID: 3754 at kernel/locking/mutex.c:564 __mutex_lock+0xc8a/0x1120 CPU: 3 UID: 0 PID: 3754 Comm: ethtool Not tainted 6.13.0-rc6+ #771 RIP: 0010:__mutex_lock+0xc8a/0x1120 Call Trace: <TASK> ethtool_check_max_channel+0x1ea/0x880 ethnl_set_channels+0x3c3/0xb10 ethnl_default_set_doit+0x306/0x650 genl_family_rcv_msg_doit+0x1e3/0x2c0 genl_rcv_msg+0x432/0x6f0 netlink_rcv_skb+0x13d/0x3b0 genl_rcv+0x28/0x40 netlink_unicast+0x42e/0x720 netlink_sendmsg+0x765/0xc20 __sys_sendto+0x3ac/0x420 __x64_sys_sendto+0xe0/0x1c0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e This is because unregister_netdevice_many_notify might run before the rtnl lock section of ethnl operations, eg. set_channels in the above example. In this example the rss lock would be destroyed by the device unregistration path before being used again, but in general running ethnl operations while dismantle has started is not a good idea. Fix this by denying any operation on devices being unregistered. A check was already there in ethnl_ops_begin, but not wide enough. Note that the same issue cannot be seen on the ioctl version (__dev_ethtool) because the device reference is retrieved from within the rtnl lock section there. Once dismantle started, the net device is unlisted and no reference will be found.

In the Linux kernel, the following vulnerability has been resolved: net: sched: Disallow replacing of child qdisc from one parent to another Lion Ackermann was able to create a UAF which can be abused for privilege escalation with the following script Step 1. create root qdisc tc qdisc add dev lo root handle 1:0 drr step2. a class for packet aggregation do demonstrate uaf tc class add dev lo classid 1:1 drr step3. a class for nesting tc class add dev lo classid 1:2 drr step4. a class to graft qdisc to tc class add dev lo classid 1:3 drr step5. tc qdisc add dev lo parent 1:1 handle 2:0 plug limit 1024 step6. tc qdisc add dev lo parent 1:2 handle 3:0 drr step7. tc class add dev lo classid 3:1 drr step 8. tc qdisc add dev lo parent 3:1 handle 4:0 pfifo step 9. Display the class/qdisc layout tc class ls dev lo class drr 1:1 root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent 3:1 limit 1000p qdisc drr 3: dev lo parent 1:2 step10. trigger the bug <=== prevented by this patch tc qdisc replace dev lo parent 1:3 handle 4:0 step 11. Redisplay again the qdiscs/classes tc class ls dev lo class drr 1:1 root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 1:3 root leaf 4: quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent 3:1 refcnt 2 limit 1000p qdisc drr 3: dev lo parent 1:2 Observe that a) parent for 4:0 does not change despite the replace request. There can only be one parent. b) refcount has gone up by two for 4:0 and c) both class 1:3 and 3:1 are pointing to it. Step 12. send one packet to plug echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10001)) step13. send one packet to the grafted fifo echo "" | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10003)) step14. lets trigger the uaf tc class delete dev lo classid 1:3 tc class delete dev lo classid 1:1 The semantics of "replace" is for a del/add _on the same node_ and not a delete from one node(3:1) and add to another node (1:3) as in step10. While we could "fix" with a more complex approach there could be consequences to expectations so the patch takes the preventive approach of "disallow such config". Joint work with Lion Ackermann <nnamrec@gmail.com>

In the Linux kernel, the following vulnerability has been resolved: gfs2: Truncate address space when flipping GFS2_DIF_JDATA flag Truncate an inode's address space when flipping the GFS2_DIF_JDATA flag: depending on that flag, the pages in the address space will either use buffer heads or iomap_folio_state structs, and we cannot mix the two.

In the Linux kernel, the following vulnerability has been resolved: drm/v3d: Ensure job pointer is set to NULL after job completion After a job completes, the corresponding pointer in the device must be set to NULL. Failing to do so triggers a warning when unloading the driver, as it appears the job is still active. To prevent this, assign the job pointer to NULL after completing the job, indicating the job has finished.

In the Linux kernel, the following vulnerability has been resolved: mm: clear uffd-wp PTE/PMD state on mremap() When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in flag clearing leads to a mismatch between the vma flags (which have uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to trigger a warning in page_table_check_pte_flags() due to setting the pte to writable while uffd-wp is still set. Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any such mremap() so that the values are consistent with the existing clearing of VM_UFFD_WP. Be careful to clear the logical flag regardless of its physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE, huge PMD and hugetlb paths.

In the Linux kernel, the following vulnerability has been resolved: platform/x86: dell-uart-backlight: fix serdev race The dell_uart_bl_serdev_probe() function calls devm_serdev_device_open() before setting the client ops via serdev_device_set_client_ops(). This ordering can trigger a NULL pointer dereference in the serdev controller's receive_buf handler, as it assumes serdev->ops is valid when SERPORT_ACTIVE is set. This is similar to the issue fixed in commit 5e700b384ec1 ("platform/chrome: cros_ec_uart: properly fix race condition") where devm_serdev_device_open() was called before fully initializing the device. Fix the race by ensuring client ops are set before enabling the port via devm_serdev_device_open(). Note, serdev_device_set_baudrate() and serdev_device_set_flow_control() calls should be after the devm_serdev_device_open() call.