CVE-2024-49942

Published Oct 21, 2024

Last updated 2 years ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/xe: Prevent null pointer access in xe_migrate_copy xe_migrate_copy designed to copy content of TTM resources. When source resource is null, it will trigger a NULL pointer dereference in xe_migrate_copy. To avoid this situation, update lacks source flag to true for this case, the flag will trigger xe_migrate_clear rather than xe_migrate_copy. Issue trace: <7> [317.089847] xe 0000:00:02.0: [drm:xe_migrate_copy [xe]] Pass 14, sizes: 4194304 & 4194304 <7> [317.089945] xe 0000:00:02.0: [drm:xe_migrate_copy [xe]] Pass 15, sizes: 4194304 & 4194304 <1> [317.128055] BUG: kernel NULL pointer dereference, address: 0000000000000010 <1> [317.128064] #PF: supervisor read access in kernel mode <1> [317.128066] #PF: error_code(0x0000) - not-present page <6> [317.128069] PGD 0 P4D 0 <4> [317.128071] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI <4> [317.128074] CPU: 1 UID: 0 PID: 1440 Comm: kunit_try_catch Tainted: G U N 6.11.0-rc7-xe #1 <4> [317.128078] Tainted: [U]=USER, [N]=TEST <4> [317.128080] Hardware name: Intel Corporation Lunar Lake Client Platform/LNL-M LP5 RVP1, BIOS LNLMFWI1.R00.3221.D80.2407291239 07/29/2024 <4> [317.128082] RIP: 0010:xe_migrate_copy+0x66/0x13e0 [xe] <4> [317.128158] Code: 00 00 48 89 8d e0 fe ff ff 48 8b 40 10 4c 89 85 c8 fe ff ff 44 88 8d bd fe ff ff 65 48 8b 3c 25 28 00 00 00 48 89 7d d0 31 ff <8b> 79 10 48 89 85 a0 fe ff ff 48 8b 00 48 89 b5 d8 fe ff ff 83 ff <4> [317.128162] RSP: 0018:ffffc9000167f9f0 EFLAGS: 00010246 <4> [317.128164] RAX: ffff8881120d8028 RBX: ffff88814d070428 RCX: 0000000000000000 <4> [317.128166] RDX: ffff88813cb99c00 RSI: 0000000004000000 RDI: 0000000000000000 <4> [317.128168] RBP: ffffc9000167fbb8 R08: ffff88814e7b1f08 R09: 0000000000000001 <4> [317.128170] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88814e7b1f08 <4> [317.128172] R13: ffff88814e7b1f08 R14: ffff88813cb99c00 R15: 0000000000000001 <4> [317.128174] FS: 0000000000000000(0000) GS:ffff88846f280000(0000) knlGS:0000000000000000 <4> [317.128176] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4> [317.128178] CR2: 0000000000000010 CR3: 000000011f676004 CR4: 0000000000770ef0 <4> [317.128180] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <4> [317.128182] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 <4> [317.128184] PKRU: 55555554 <4> [317.128185] Call Trace: <4> [317.128187] <TASK> <4> [317.128189] ? show_regs+0x67/0x70 <4> [317.128194] ? __die_body+0x20/0x70 <4> [317.128196] ? __die+0x2b/0x40 <4> [317.128198] ? page_fault_oops+0x15f/0x4e0 <4> [317.128203] ? do_user_addr_fault+0x3fb/0x970 <4> [317.128205] ? lock_acquire+0xc7/0x2e0 <4> [317.128209] ? exc_page_fault+0x87/0x2b0 <4> [317.128212] ? asm_exc_page_fault+0x27/0x30 <4> [317.128216] ? xe_migrate_copy+0x66/0x13e0 [xe] <4> [317.128263] ? __lock_acquire+0xb9d/0x26f0 <4> [317.128265] ? __lock_acquire+0xb9d/0x26f0 <4> [317.128267] ? sg_free_append_table+0x20/0x80 <4> [317.128271] ? lock_acquire+0xc7/0x2e0 <4> [317.128273] ? mark_held_locks+0x4d/0x80 <4> [317.128275] ? trace_hardirqs_on+0x1e/0xd0 <4> [317.128278] ? _raw_spin_unlock_irqrestore+0x31/0x60 <4> [317.128281] ? __pm_runtime_resume+0x60/0xa0 <4> [317.128284] xe_bo_move+0x682/0xc50 [xe] <4> [317.128315] ? lock_is_held_type+0xaa/0x120 <4> [317.128318] ttm_bo_handle_move_mem+0xe5/0x1a0 [ttm] <4> [317.128324] ttm_bo_validate+0xd1/0x1a0 [ttm] <4> [317.128328] shrink_test_run_device+0x721/0xc10 [xe] <4> [317.128360] ? find_held_lock+0x31/0x90 <4> [317.128363] ? lock_release+0xd1/0x2a0 <4> [317.128365] ? __pfx_kunit_generic_run_threadfn_adapter+0x10/0x10 [kunit] <4> [317.128370] xe_bo_shrink_kunit+0x11/0x20 [xe] <4> [317.128397] kunit_try_run_case+0x6e/0x150 [kunit] <4> [317.128400] ? trace_hardirqs_on+0x1e/0xd0 <4> [317.128402] ? _raw_spin_unlock_irqrestore+0x31/0x60 <4> [317.128404] kunit_generic_run_threadfn_adapter+0x1e/0x40 [ku ---truncated---
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
CWE-476

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