syzbot


KMSAN: uninit-value in sk_filter_trim_cap (2)

Status: closed as invalid on 2020/07/22 14:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 799d, last: 797d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in sk_filter_trim_cap syz 2 850d 850d 0/24 closed as invalid on 2020/05/28 10:53

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in sk_filter_trim_cap+0x828/0xcc0 net/core/filter.c:121
CPU: 0 PID: 8472 Comm: syz-executor467 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1df/0x240 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 sk_filter_trim_cap+0x828/0xcc0 net/core/filter.c:121
 sk_filter include/linux/filter.h:831 [inline]
 unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710
 unix_seqpacket_sendmsg+0x26c/0x2e0 net/unix/af_unix.c:2063
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmmsg+0x60e/0xd80 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2522
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2522
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4402e9
Code: Bad RIP value.
RSP: 002b:00007ffe1ebab908 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402e9
RDX: 03fffffffffffe36 RSI: 0000000020001e00 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401af0
R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline]
 __bpf_prog_run_save_cb include/linux/filter.h:691 [inline]
 bpf_prog_run_save_cb include/linux/filter.h:705 [inline]
 sk_filter_trim_cap+0x42a/0xcc0 net/core/filter.c:119
 sk_filter include/linux/filter.h:831 [inline]
 unix_dgram_sendmsg+0x1987/0x3c30 net/unix/af_unix.c:1710
 unix_seqpacket_sendmsg+0x26c/0x2e0 net/unix/af_unix.c:2063
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmmsg+0x60e/0xd80 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg+0xbd/0xe0 net/socket.c:2522
 __x64_sys_sendmmsg+0x56/0x70 net/socket.c:2522
 do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Local variable ----regs@__bpf_prog_run32 created at:
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
=====================================================

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kmsan-gce 2020/07/19 21:16 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report syz C
ci-upstream-kmsan-gce-386 2020/07/19 23:28 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report syz C
ci-upstream-kmsan-gce 2020/07/18 12:21 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report
ci-upstream-kmsan-gce 2020/07/18 06:58 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report
ci-upstream-kmsan-gce 2020/07/17 19:27 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report
ci-upstream-kmsan-gce 2020/07/17 19:22 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report
ci-upstream-kmsan-gce-386 2020/07/18 09:32 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report
* Struck through repros no longer work on HEAD.