syzbot


KMSAN: uninit-value in sctp_assoc_bh_rcv

Status: upstream: reported on 2025/04/05 04:40
Subsystems: sctp
[Documentation on labels]
Reported-by: syzbot+773e51afe420baaf0e2b@syzkaller.appspotmail.com
First crash: 6d20h, last: 33m
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [sctp?] KMSAN: uninit-value in sctp_assoc_bh_rcv 0 (1) 2025/04/05 04:40

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in sctp_assoc_bh_rcv+0x38e/0xc50 net/sctp/associola.c:1005
 sctp_assoc_bh_rcv+0x38e/0xc50 net/sctp/associola.c:1005
 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331
 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1126
 __release_sock+0x1da/0x330 net/core/sock.c:3158
 release_sock+0x6b/0x250 net/core/sock.c:3712
 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360
 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885
 sctp_sendmsg+0x32b9/0x4a90 net/sctp/socket.c:2031
 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x267/0x380 net/socket.c:727
 __sys_sendto+0x594/0x750 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0x125/0x1d0 net/socket.c:2183
 x64_sys_call+0x37e7/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4157 [inline]
 slab_alloc_node mm/slub.c:4200 [inline]
 __do_kmalloc_node mm/slub.c:4330 [inline]
 __kmalloc_node_track_caller_noprof+0x962/0x1260 mm/slub.c:4350
 kmalloc_reserve+0x23e/0x4a0 net/core/skbuff.c:599
 __alloc_skb+0x366/0x7b0 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1340 [inline]
 sctp_packet_pack net/sctp/output.c:472 [inline]
 sctp_packet_transmit+0x1811/0x4470 net/sctp/output.c:621
 sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline]
 sctp_outq_flush+0x1b2f/0x6590 net/sctp/outqueue.c:1221
 sctp_outq_uncork+0x9c/0xb0 net/sctp/outqueue.c:764
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
 sctp_do_sm+0x8c5d/0x93e0 net/sctp/sm_sideeffect.c:1169
 sctp_assoc_bh_rcv+0x8fe/0xc50 net/sctp/associola.c:1052
 sctp_inq_push+0x2ef/0x380 net/sctp/inqueue.c:88
 sctp_backlog_rcv+0x397/0xdb0 net/sctp/input.c:331
 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1126
 __release_sock+0x1da/0x330 net/core/sock.c:3158
 release_sock+0x6b/0x250 net/core/sock.c:3712
 sctp_wait_for_connect+0x487/0x820 net/sctp/socket.c:9360
 sctp_sendmsg_to_asoc+0x1ec1/0x1f00 net/sctp/socket.c:1885
 sctp_sendmsg+0x32b9/0x4a90 net/sctp/socket.c:2031
 inet_sendmsg+0x25a/0x280 net/ipv4/af_inet.c:851
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x267/0x380 net/socket.c:727
 __sys_sendto+0x594/0x750 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0x125/0x1d0 net/socket.c:2183
 x64_sys_call+0x37e7/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:45
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 22298 Comm: syz.4.4296 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
=====================================================

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/07 20:50 upstream 0af2f6be1b42 a2ada0e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/07 19:34 upstream 0af2f6be1b42 a2ada0e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/03 18:42 upstream a2cc6ff5ec8f 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/03 06:00 upstream 92b71befc349 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/02 08:09 upstream acc4d5ff0b61 c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/02 01:00 upstream 08733088b566 d863cf4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/01 04:39 upstream 4e82c87058f4 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/08 00:42 upstream 0af2f6be1b42 a2ada0e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/06 10:42 upstream f4d2ef48250a 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/06 10:42 upstream f4d2ef48250a 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/06 10:36 upstream f4d2ef48250a 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/03 09:28 upstream 92b71befc349 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/02 13:38 upstream acc4d5ff0b61 c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
2025/04/01 05:41 upstream 609706855d90 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in sctp_assoc_bh_rcv
* Struck through repros no longer work on HEAD.