CVE-2024-41057
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2024-41057
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-41057.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-41057
- Downstream
- Related
- Published
- 2024-07-29T14:57:19Z
- Modified
- 2025-10-17T09:23:27.885580Z
- Summary
- cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix slab-use-after-free in cachefileswithdrawcookie()
We got the following issue in our fault injection stress test:
================================================================== BUG: KASAN: slab-use-after-free in cachefileswithdrawcookie+0x4d9/0x600 Read of size 8 at addr ffff888118efc000 by task kworker/u78:0/109
CPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566 Call Trace: <TASK> kasanreport+0x93/0xc0 cachefileswithdrawcookie+0x4d9/0x600 fscachecookiestatemachine+0x5c8/0x1230 fscachecookieworker+0x91/0x1c0 processonework+0x7fa/0x1800 [...]
Allocated by task 117: kmalloctrace+0x1b3/0x3c0 cachefilesacquirevolume+0xf3/0x9c0 fscachecreatevolumework+0x97/0x150 processonework+0x7fa/0x1800 [...]
Freed by task 120301: kfree+0xf1/0x2c0 cachefileswithdrawcache+0x3fa/0x920 cachefilesputunbindpincount+0x1f6/0x250 cachefilesdaemonrelease+0x13b/0x290 _fput+0x204/0xa00 taskworkrun+0x139/0x230 do_exit+0x87a/0x29b0
[...]
Following is the process that triggers the issue:
p1 | p2
fscache_begin_lookup fscache_begin_volume_access fscache_cache_is_live(fscache_cache)cachefilesdaemonrelease cachefilesputunbindpincount cachefilesdaemonunbind cachefileswithdrawcache fscachewithdrawcache fscachesetcachestate(cache, FSCACHECACHEISWITHDRAWN); cachefileswithdrawobjects(cache) fscachewaitforobjects(fscache) atomicread(&fscachecache->objectcount) == 0 fscacheperformlookup cachefileslookupcookie cachefilesallocobject refcountset(&object->ref, 1); object->volume = volume fscachecountobject(vcookie->cache); atomicinc(&fscachecache->objectcount) cachefileswithdrawvolumes cachefileswithdrawvolume fscachewithdrawvolume _cachefilesfreevolume kfree(cachefilesvolume) fscachecookiestatemachine cachefileswithdrawcookie cache = object->volume->cache; // cachefiles_volume UAF !!!
After setting FSCACHECACHEISWITHDRAWN, wait for all the cookie lookups to complete first, and then wait for fscachecache->objectcount == 0 to avoid the cookie exiting after the volume has been freed and triggering the above issue. Therefore call fscachewithdrawvolume() before calling cachefileswithdraw_objects().
This way, after setting FSCACHECACHEISWITHDRAWN, only the following two cases will occur: 1) fscachebeginlookup fails in fscachebeginvolumeaccess(). 2) fscachewithdrawvolume() will ensure that fscachecountobject() has been executed before calling fscachewaitfor_objects().
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/5d8f805789072ea7fd39504694b7bd17e5f751c4
- https://git.kernel.org/stable/c/8de253177112a47c9af157d23ae934779188b4e1
- https://git.kernel.org/stable/c/9e67589a4a7b7e5660b524d1d5fe61242bcbcc11
- https://git.kernel.org/stable/c/ef81340401e8a371d6b17f69e76d861920972cfe
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfe2140e2f57fef8562e0f9b7cd447d2b08dc2f35Fixed8de253177112a47c9af157d23ae934779188b4e1
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfe2140e2f57fef8562e0f9b7cd447d2b08dc2f35Fixed9e67589a4a7b7e5660b524d1d5fe61242bcbcc11
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfe2140e2f57fef8562e0f9b7cd447d2b08dc2f35Fixedef81340401e8a371d6b17f69e76d861920972cfe
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedfe2140e2f57fef8562e0f9b7cd447d2b08dc2f35Fixed5d8f805789072ea7fd39504694b7bd17e5f751c4