In the Linux kernel, the following vulnerability has been resolved:
procfs: avoid fetching build ID while holding VMA lock
Fix PROCMAP_QUERY to fetch optional build ID only after dropping mmap_lock
or per-VMA lock, whichever was used to lock VMA under question, to avoid
deadlock reported by syzbot:
-> #1 (&mm->mmap_lock){++++}-{4:4}:
__might_fault+0xed/0x170
_copy_to_iter+0x118/0x1720
copy_page_to_iter+0x12d/0x1e0
filemap_read+0x720/0x10a0
blkdev_read_iter+0x2b5/0x4e0
vfs_read+0x7f4/0xae0
ksys_read+0x12a/0x250
do_syscall_64+0xcb/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&sb->s_type->i_mutex_key#8){++++}-{4:4}:
__lock_acquire+0x1509/0x26d0
lock_acquire+0x185/0x340
down_read+0x98/0x490
blkdev_read_iter+0x2a7/0x4e0
__kernel_read+0x39a/0xa90
freader_fetch+0x1d5/0xa80
__build_id_parse.isra.0+0xea/0x6a0
do_procmap_query+0xd75/0x1050
procfs_procmap_ioctl+0x7a/0xb0
__x64_sys_ioctl+0x18e/0x210
do_syscall_64+0xcb/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#8);
lock(&mm->mmap_lock);
rlock(&sb->s_type->i_mutex_key#8);
*** DEADLOCK ***
This seems to be exacerbated (as we haven't seen these syzbot reports
before that) by the recent:
777a8560fd29 ("lib/buildid: use __kernel_read() for sleepable context")
To make this safe, we need to grab file refcount while VMA is still locked, but
other than that everything is pretty straightforward. Internal build_id_parse()
API assumes VMA is passed, but it only needs the underlying file reference, so
just add another variant build_id_parse_file() that expects file passed
directly.
[akpm@linux-foundation.org: fix up kerneldoc]
References
Configurations
Configuration 1 (hide)
|
History
19 Mar 2026, 16:41
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/b5cbacd7f86f4f62b8813688c8e73be94e8e1951 - Patch | |
| References | () https://git.kernel.org/stable/c/b9b97e6aeb534315f9646b2090d1a5024c6a4e82 - Patch | |
| References | () https://git.kernel.org/stable/c/cbc03ce3e6ce7e21214c3f02218213574c1a2d08 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| First Time |
Linux
Linux linux Kernel |
|
| CWE | CWE-667 |
18 Feb 2026, 17:52
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
14 Feb 2026, 17:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-02-14 17:15
Updated : 2026-03-19 16:41
NVD link : CVE-2026-23199
Mitre link : CVE-2026-23199
CVE.ORG link : CVE-2026-23199
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-667
Improper Locking
