Use of Uninitialized Resource Affecting kernel-devel package, versions <0:4.18.0-553.5.1.el8_10

Note: Versions mentioned in the description apply only to the upstream kernel-devel package and not the kernel-devel package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:8 relevant fixed versions and status.

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.

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-26901
• https://git.kernel.org/stable/c/3948abaa4e2be938ccdfc289385a27342fb13d43
• https://git.kernel.org/stable/c/423b6bdf19bbc5e1f7e7461045099917378f7e71
• https://git.kernel.org/stable/c/4bac28f441e3cc9d3f1a84c8d023228a68d8a7c1
• https://git.kernel.org/stable/c/772a7def9868091da3bcb0d6c6ff9f0c03d7fa8b
• https://git.kernel.org/stable/c/bf9ec1b24ab4e94345aa1c60811dd329f069c38b
• https://git.kernel.org/stable/c/c1362eae861db28b1608b9dc23e49634fe87b63b
• https://git.kernel.org/stable/c/cba138f1ef37ec6f961baeab62f312dedc7cf730
• https://git.kernel.org/stable/c/cde76b3af247f615447bcfecf610bb76c3529126
• https://git.kernel.org/stable/c/e6450d5e46a737a008b4885aa223486113bf0ad6
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html