Description

In the Linux kernel, the following vulnerability has been resolved:

cachefiles: fix memory leak in cachefiles_add_cache()

The following memory leak was reported after unbinding /dev/cachefiles:

==================================================================
unreferenced object 0xffff9b674176e3c0 (size 192):
comm "cachefilesd2", pid 680, jiffies 4294881224
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc ea38a44b):
[] kmem_cache_alloc+0x2d5/0x370
[] prepare_creds+0x26/0x2e0
[] cachefiles_determine_cache_security+0x1f/0x120
[] cachefiles_add_cache+0x13c/0x3a0
[] cachefiles_daemon_write+0x146/0x1c0
[] vfs_write+0xcb/0x520
[] ksys_write+0x69/0xf0
[] do_syscall_64+0x72/0x140
[] entry_SYSCALL_64_after_hwframe+0x6e/0x76
==================================================================

Put the reference count of cache_cred in cachefiles_daemon_unbind() to
fix the problem. And also put cache_cred in cachefiles_add_cache() error
branch to avoid memory leaks.

Classification

CVE ID: CVE-2024-26840

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.08% (scored less or equal to compared to others)

EPSS Date: 2025-02-04 (when was this score calculated)

References

https://git.kernel.org/stable/c/cb5466783793e66272624cf71925ae1d1ba32083
https://git.kernel.org/stable/c/037d5a949b0455540ef9aab34c10ddf54b65d285
https://git.kernel.org/stable/c/43eccc5823732ba6daab2511ed32dfc545a666d8
https://git.kernel.org/stable/c/94965be37add0983672e48ecb33cdbda92b62579
https://git.kernel.org/stable/c/8b218e2f0a27a9f09428b1847b4580640b9d1e58
https://git.kernel.org/stable/c/38e921616320d159336b0ffadb09e9fb4945c7c3
https://git.kernel.org/stable/c/9cac69912052a4def571fedf1cb9bb4ec590e25a
https://git.kernel.org/stable/c/e21a2f17566cbd64926fb8f16323972f7a064444

Timeline