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

afs: Fix endless loop in directory parsing

If a directory has a block with only ".__afsXXXX" files in it (from
uncompleted silly-rename), these .__afsXXXX files are skipped but without
advancing the file position in the dir_context. This leads to
afs_dir_iterate() repeating the block again and again.

Fix this by making the code that skips the .__afsXXXX file also manually
advance the file position.

The symptoms are a soft lookup:

    watchdog: BUG: soft lockup - CPU#3 stuck for 52s! [check:5737]
    ...
    RIP: 0010:afs_dir_iterate_block+0x39/0x1fd
    ...
     ? watchdog_timer_fn+0x1a6/0x213
    ...
     ? asm_sysvec_apic_timer_interrupt+0x16/0x20
     ? afs_dir_iterate_block+0x39/0x1fd
     afs_dir_iterate+0x10a/0x148
     afs_readdir+0x30/0x4a
     iterate_dir+0x93/0xd3
     __do_sys_getdents64+0x6b/0xd4

This is almost certainly the actual fix for:

    https://bugzilla.kernel.org/show_bug.cgi?id=218496

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-26848
• https://git.kernel.org/stable/c/058ed71e0f7aa3b6694ca357e23d084e5d3f2470
• https://git.kernel.org/stable/c/106e14ca55a0acb3236ee98813a1d243f8aa2d05
• https://git.kernel.org/stable/c/2afdd0cb02329464d77f3ec59468395c791a51a4
• https://git.kernel.org/stable/c/5c78be006ed9cb735ac2abf4fd64f3f4ea26da31
• https://git.kernel.org/stable/c/5f7a07646655fb4108da527565dcdc80124b14c4
• https://git.kernel.org/stable/c/76426abf9b980b46983f97de8e5b25047b4c9863
• https://git.kernel.org/stable/c/80b15346492bdba677bbb0adefc611910e505f7b
• https://git.kernel.org/stable/c/854ebf45a4ddd4cadeffb6644e88d19020634e1a
• https://git.kernel.org/stable/c/96370ba395c572ef496fd2c7afc4a1ab3dedd3f0
• https://git.kernel.org/stable/c/9c41f4935625218a2053a2dce1423c3054169809
• https://git.kernel.org/stable/c/a6ffae61ad9ebf2fdcb943135b2f30c85f49cd27
• https://git.kernel.org/stable/c/b94f434fe977689da4291dc21717790b9bd1c064
• https://git.kernel.org/stable/c/f67898867b6b0f4542cddc7fe57997978b948a7a
• https://git.kernel.org/stable/c/fe02316e4933befc621fa125efb8f8b4d04cceec
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html