In the Linux kernel, the following vulnerability has been resolved:
list: fix a data-race around ep->rdllist
ep_poll() first calls ep_events_available() with no lock held and checks
if ep->rdllist is empty by list_empty_careful(), which reads
rdllist->prev. Thus all accesses to it need some protection to avoid
store/load-tearing.
Note INIT_LIST_HEAD_RCU() already has the annotation for both prev
and next.
Commit bf3b9f6372c4 ("epoll: Add busy poll support to epoll with socket
fds.") added the first lockless ep_events_available(), and commit
c5a282e9635e ("fs/epoll: reduce the scope of wq lock in epoll_wait()")
made some ep_events_available() calls lockless and added single call under
a lock, finally commit e59d3c64cba6 ("epoll: eliminate unnecessary lock
for zero timeout") made the last ep_events_available() lockless.
BUG: KCSAN: data-race in do_epoll_wait / do_epoll_wait
write to 0xffff88810480c7d8 of 8 bytes by task 1802 on cpu 0:
INIT_LIST_HEAD include/linux/list.h:38 [inline]
list_splice_init include/linux/list.h:492 [inline]
ep_start_scan fs/eventpoll.c:622 [inline]
ep_send_events fs/eventpoll.c:1656 [inline]
ep_poll fs/eventpoll.c:1806 [inline]
do_epoll_wait+0x4eb/0xf40 fs/eventpoll.c:2234
do_epoll_pwait fs/eventpoll.c:2268 [inline]
__do_sys_epoll_pwait fs/eventpoll.c:2281 [inline]
__se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275
__x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
read to 0xffff88810480c7d8 of 8 bytes by task 1799 on cpu 1:
list_empty_careful include/linux/list.h:329 [inline]
ep_events_available fs/eventpoll.c:381 [inline]
ep_poll fs/eventpoll.c:1797 [inline]
do_epoll_wait+0x279/0xf40 fs/eventpoll.c:2234
do_epoll_pwait fs/eventpoll.c:2268 [inline]
__do_sys_epoll_pwait fs/eventpoll.c:2281 [inline]
__se_sys_epoll_pwait+0x12b/0x240 fs/eventpoll.c:2275
__x64_sys_epoll_pwait+0x74/0x80 fs/eventpoll.c:2275
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
value changed: 0xffff88810480c7d0 -> 0xffff888103c15098
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1799 Comm: syz-fuzzer Tainted: G W 5.17.0-rc7-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
References
Configurations
Configuration 1 (hide)
|
History
17 Mar 2025, 16:53
Type | Values Removed | Values Added |
---|---|---|
Summary |
|
|
CVSS |
v2 : v3 : |
v2 : unknown
v3 : 4.7 |
CWE | CWE-362 | |
References | () https://git.kernel.org/stable/c/5d5d993f16be15d124be7b8ec71b28ef7b7dc3af - Patch | |
References | () https://git.kernel.org/stable/c/cb3e48f7a35033deb9455abe3932e63cb500b9eb - Patch | |
References | () https://git.kernel.org/stable/c/d679ae94fdd5d3ab00c35078f5af5f37e068b03d - Patch | |
References | () https://git.kernel.org/stable/c/e039c0b5985999b150594126225e1ee51df7b4c9 - Patch | |
CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
First Time |
Linux linux Kernel
Linux |
26 Feb 2025, 07:01
Type | Values Removed | Values Added |
---|---|---|
New CVE |
Information
Published : 2025-02-26 07:01
Updated : 2025-03-17 16:53
NVD link : CVE-2022-49443
Mitre link : CVE-2022-49443
CVE.ORG link : CVE-2022-49443
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')