Description

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

smb: client: fix UAF in async decryption

Doing an async decryption (large read) crashes with a
slab-use-after-free way down in the crypto API.

Reproducer:
# mount.cifs -o ...,seal,esize=1 //srv/share /mnt
# dd if=/mnt/largefile of=/dev/null
...
[ 194.196391] ==================================================================
[ 194.196844] BUG: KASAN: slab-use-after-free in gf128mul_4k_lle+0xc1/0x110
[ 194.197269] Read of size 8 at addr ffff888112bd0448 by task kworker/u77:2/899
[ 194.197707]
[ 194.197818] CPU: 12 UID: 0 PID: 899 Comm: kworker/u77:2 Not tainted 6.11.0-lku-00028-gfca3ca14a17a-dirty #43
[ 194.198400] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-3-gd478f380-prebuilt.qemu.org 04/01/2014
[ 194.199046] Workqueue: smb3decryptd smb2_decrypt_offload [cifs]
[ 194.200032] Call Trace:
[ 194.200191]
[ 194.200327] dump_stack_lvl+0x4e/0x70
[ 194.200558] ? gf128mul_4k_lle+0xc1/0x110
[ 194.200809] print_report+0x174/0x505
[ 194.201040] ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[ 194.201352] ? srso_return_thunk+0x5/0x5f
[ 194.201604] ? __virt_addr_valid+0xdf/0x1c0
[ 194.201868] ? gf128mul_4k_lle+0xc1/0x110
[ 194.202128] kasan_report+0xc8/0x150
[ 194.202361] ? gf128mul_4k_lle+0xc1/0x110
[ 194.202616] gf128mul_4k_lle+0xc1/0x110
[ 194.202863] ghash_update+0x184/0x2...

Classification

CVE ID: CVE-2024-50047

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.04% (probability of being exploited)

EPSS Percentile: 5.0% (scored less or equal to compared to others)

EPSS Date: 2025-03-03 (when was this score calculated)

References

https://git.kernel.org/stable/c/bce966530fd5542bbb422cb45ecb775f7a1a6bc3
https://git.kernel.org/stable/c/0809fb86ad13b29e1d6d491364fc7ea4fb545995
https://git.kernel.org/stable/c/538c26d9bf70c90edc460d18c81008a4e555925a
https://git.kernel.org/stable/c/b0abcd65ec545701b8793e12bc27dc98042b151a

Timeline