CVE-2024-26901 do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak
A local attacker can read uninitialized kernel memory via the name_to_handle_at syscall, potentially exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-26901?
CVE-2024-26901 is a medium-severity vulnerability in Linux kernel, published on 17 Apr 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak
syzbot identified a kernel information leak vulnerability in do_sys_name_to_handle() and issued the following report [1].
[1] "BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ...
Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] do_sys_name_to_handle fs/fhandle.c:39 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ...
Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff888128a46380 Data copied to user address 0000000020000240"
Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to solve the problem.
Weakness: CWE-908
Which versions are affected by CVE-2024-26901?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26901?
Apply the vendor's patch.
Is CVE-2024-26901 being exploited?
There is no known exploitation of CVE-2024-26901 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-40082, BELL-CVE-2024-26901, DEBIAN-CVE-2024-26901, GHSA-jwqh-57hr-2ggg, UBUNTU-CVE-2024-26901.