syzbot


KMSAN: uninit-value in af_alg_free_sg (2)

Status: fixed on 2024/03/25 23:45
Subsystems: crypto
[Documentation on labels]
Reported-by: syzbot+3266db0c26d1fbbe3abb@syzkaller.appspotmail.com
Fix commit: 24c890dd712f crypto: algif_hash - Remove bogus SGL free on zero-length error path
First crash: 98d, last: 98d
Discussions (3)
Title Replies (including bot) Last reply
[PATCH] crypto: algif_hash - Remove bogus SGL free on zero-length error path 2 (2) 2024/02/01 05:53
Re: [syzbot] [crypto?] KMSAN: uninit-value in af_alg_free_sg (2) 1 (1) 2024/01/26 13:11
[syzbot] [crypto?] KMSAN: uninit-value in af_alg_free_sg (2) 0 (1) 2024/01/14 10:15
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in af_alg_free_sg crypto C 2 129d 129d 0/26 closed as invalid on 2023/12/29 13:45

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in af_alg_free_sg+0x1a7/0x270 crypto/af_alg.c:547
 af_alg_free_sg+0x1a7/0x270 crypto/af_alg.c:547
 hash_sendmsg+0x1938/0x1c30 crypto/algif_hash.c:172
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2586
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2640
 __sys_sendmmsg+0x3c4/0x950 net/socket.c:2726
 __do_sys_sendmmsg net/socket.c:2755 [inline]
 __se_sys_sendmmsg net/socket.c:2752 [inline]
 __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2752
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

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]
 sock_kmalloc+0x128/0x1c0 net/core/sock.c:2688
 hash_accept_parent_nokey crypto/algif_hash.c:418 [inline]
 hash_accept_parent+0xbf/0x430 crypto/algif_hash.c:445
 af_alg_accept+0x1fc/0x810 crypto/af_alg.c:439
 hash_accept+0x340/0x790 crypto/algif_hash.c:254
 do_accept+0x606/0xa80 net/socket.c:1929
 __sys_accept4_file net/socket.c:1969 [inline]
 __sys_accept4+0x18e/0x360 net/socket.c:1999
 __do_sys_accept4 net/socket.c:2010 [inline]
 __se_sys_accept4 net/socket.c:2007 [inline]
 __x64_sys_accept4+0xb8/0x120 net/socket.c:2007
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 1 PID: 6735 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/08 16:12 upstream 0dd3ee311255 4c0fd4bb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in af_alg_free_sg
* Struck through repros no longer work on HEAD.