===================================================== BUG: KMSAN: uninit-value in sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a0/0xbc0 net/sctp/associola.c:980 sctp_inq_push+0x2a6/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_sendmsg+0x3a2b/0x49f0 net/sctp/socket.c:2037 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x3bf/0x7c0 net/socket.c:2702 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0xd2/0x160 net/compat.c:364 ia32_sys_call+0x3a66/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:346 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Uninit was stored to memory at: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 19251 at kernel/stacktrace.c:29 stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29 Modules linked in: CPU: 0 UID: 0 PID: 19251 Comm: syz.0.3133 Not tainted 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 PREEMPT(undef) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:stack_trace_print+0xd4/0xf0 kernel/stacktrace.c:29 Code: 1e 83 02 92 89 de ba 20 00 00 00 4c 89 e1 e8 23 7b 4d ff 49 83 c6 08 49 ff cd 0f 85 6e ff ff ff eb 0b e8 4f 96 c3 00 eb d4 90 <0f> 0b 90 5b 41 5c 41 5d 41 5e 41 5f 5d e9 da 4e f3 0e cc 66 0f 1f RSP: 0018:ffff88803394f058 EFLAGS: 00010246 RAX: ffff888064552c18 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88803394f080 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88803314f098 R11: 0000000000011ed0 R12: 0000000000000000 R13: 00000000abcd0100 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881aa87f000(0063) knlGS:00000000f50b6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007fb14aa4ea10 CR3: 0000000064572000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kmsan_print_origin+0xb0/0x340 mm/kmsan/report.c:133 kmsan_report+0x1d3/0x320 mm/kmsan/report.c:196 __msan_warning+0x1b/0x30 mm/kmsan/instrumentation.c:315 sctp_inq_pop+0x14dc/0x19e0 net/sctp/inqueue.c:211 sctp_assoc_bh_rcv+0x1a0/0xbc0 net/sctp/associola.c:980 sctp_inq_push+0x2a6/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_sendmsg+0x3a2b/0x49f0 net/sctp/socket.c:2037 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x3bf/0x7c0 net/socket.c:2702 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0xd2/0x160 net/compat.c:364 ia32_sys_call+0x3a66/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:346 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f91539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f50b655c EFLAGS: 00000206 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080003f00 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace 0000000000000000 ]--- Uninit was created at: slab_post_alloc_hook mm/slub.c:4154 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4249 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:579 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] sctp_packet_pack net/sctp/output.c:472 [inline] sctp_packet_transmit+0x18a1/0x46d0 net/sctp/output.c:621 sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline] sctp_outq_flush+0x1c7d/0x67c0 net/sctp/outqueue.c:1221 sctp_outq_uncork+0x9e/0xc0 net/sctp/outqueue.c:764 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x8c8e/0x9720 net/sctp/sm_sideeffect.c:1175 sctp_assoc_bh_rcv+0x88b/0xbc0 net/sctp/associola.c:1034 sctp_inq_push+0x2a6/0x350 net/sctp/inqueue.c:88 sctp_backlog_rcv+0x3c7/0xda0 net/sctp/input.c:331 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 sctp_sendmsg+0x3a2b/0x49f0 net/sctp/socket.c:2037 inet_sendmsg+0x269/0x2a0 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x278/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x3bf/0x7c0 net/socket.c:2702 __compat_sys_sendmmsg net/compat.c:360 [inline] __do_compat_sys_sendmmsg net/compat.c:367 [inline] __se_compat_sys_sendmmsg net/compat.c:364 [inline] __ia32_compat_sys_sendmmsg+0xd2/0x160 net/compat.c:364 ia32_sys_call+0x3a66/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:346 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369 entry_SYSENTER_compat_after_hwframe+0x84/0x8e CPU: 0 UID: 0 PID: 19251 Comm: syz.0.3133 Tainted: G W 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 PREEMPT(undef) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ===================================================== ---------------- Code disassembly (best guess): 0: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 4: 10 07 adc %al,(%rdi) 6: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi a: 10 08 adc %cl,(%rax) c: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop