CVE-2022-48795

Published Jul 16, 2024

Last updated 8 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: parisc: Fix data TLB miss in sba_unmap_sg Rolf Eike Beer reported the following bug: [1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018 [1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4 [1274934.746891] Hardware name: 9000/785/C8000 [1274934.746891] [1274934.746891] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI [1274934.746891] PSW: 00001000000001001111111000001110 Not tainted [1274934.746891] r00-03 000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000 [1274934.746891] r04-07 0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001 [1274934.746891] r08-11 0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001 [1274934.746891] r12-15 0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0 [1274934.746891] r16-19 0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007 [1274934.746891] r20-23 0000000000000006 000000004a368950 0000000000000000 0000000000000001 [1274934.746891] r24-27 0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0 [1274934.746891] r28-31 0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118 [1274934.746891] sr00-03 00000000066e5800 0000000000000000 0000000000000000 00000000066e5800 [1274934.746891] sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [1274934.746891] [1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec [1274934.746891] IIR: 48780030 ISR: 0000000000000000 IOR: 0000004140000018 [1274934.746891] CPU: 3 CR30: 00000040e3a9c000 CR31: ffffffffffffffff [1274934.746891] ORIG_R28: 0000000040acdd58 [1274934.746891] IAOQ[0]: sba_unmap_sg+0xb0/0x118 [1274934.746891] IAOQ[1]: sba_unmap_sg+0xb4/0x118 [1274934.746891] RP(r2): sba_unmap_sg+0xac/0x118 [1274934.746891] Backtrace: [1274934.746891] [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70 [1274934.746891] [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60 [1274934.746891] [<00000000407a3488>] mptscsih_io_done+0x150/0xd70 [1274934.746891] [<0000000040798600>] mpt_interrupt+0x168/0xa68 [1274934.746891] [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278 [1274934.746891] [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8 [1274934.746891] [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0 [1274934.746891] [<00000000402548e0>] generic_handle_irq+0x50/0x70 [1274934.746891] [<000000004019a254>] call_on_stack+0x18/0x24 [1274934.746891] [1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?) The bug is caused by overrunning the sglist and incorrectly testing sg_dma_len(sglist) before nents. Normally this doesn't cause a crash, but in this case sglist crossed a page boundary. This occurs in the following code: while (sg_dma_len(sglist) && nents--) { The fix is simply to test nents first and move the decrement of nents into the loop.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272