On Mon, Feb 24, 2020 at 3:28 AM syzbot <syzbot+e4b12d8d202701f08...@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 8bbbc5cf kmsan: don't compile memmove > git tree: https://github.com/google/kmsan.git master > console output: https://syzkaller.appspot.com/x/log.txt?x=11d7c109e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=cd0e9a6b0e555cc3 > dashboard link: https://syzkaller.appspot.com/bug?extid=e4b12d8d202701f08b6d > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ > c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > userspace arch: i386 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1287fdd9e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ffec81e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+e4b12d8d202701f08...@syzkaller.appspotmail.com > > ===================================================== > BUG: KMSAN: uninit-value in string_nocheck lib/vsprintf.c:608 [inline] > BUG: KMSAN: uninit-value in string+0x522/0x690 lib/vsprintf.c:689 > CPU: 1 PID: 12069 Comm: syz-executor170 Not tainted 5.6.0-rc2-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+0x1c9/0x220 lib/dump_stack.c:118 > kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 > __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 > string_nocheck lib/vsprintf.c:608 [inline] > string+0x522/0x690 lib/vsprintf.c:689 > vsnprintf+0x207d/0x31b0 lib/vsprintf.c:2574 > audit_log_vformat+0x583/0xcd0 kernel/audit.c:1856 > audit_log_format+0x220/0x260 kernel/audit.c:1890 > audit_receive_msg kernel/audit.c:1338 [inline] > audit_receive+0x3688/0x6be0 kernel/audit.c:1513 > netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] > netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1328 > netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1917 > sock_sendmsg_nosec net/socket.c:652 [inline] > sock_sendmsg net/socket.c:672 [inline] > ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343 > ___sys_sendmsg net/socket.c:2397 [inline] > __sys_sendmsg+0x451/0x5f0 net/socket.c:2430 > __compat_sys_sendmsg net/compat.c:642 [inline] > __do_compat_sys_sendmsg net/compat.c:649 [inline] > __se_compat_sys_sendmsg net/compat.c:646 [inline] > __ia32_compat_sys_sendmsg+0xed/0x130 net/compat.c:646 > do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] > do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410 > entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 > RIP: 0023:0xf7f12d99 > Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 > 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 > 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 > RSP: 002b:00000000ffadf8ac EFLAGS: 00000246 ORIG_RAX: 0000000000000172 > RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000200 > RDX: 0000000000000000 RSI: 00000000080ea080 RDI: 00000000ffadf900 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] > kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 > kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82 > slab_alloc_node mm/slub.c:2793 [inline] > __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401 > __kmalloc_reserve net/core/skbuff.c:142 [inline] > __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210 > alloc_skb include/linux/skbuff.h:1051 [inline] > netlink_alloc_large_skb net/netlink/af_netlink.c:1174 [inline] > netlink_sendmsg+0x7d3/0x14d0 net/netlink/af_netlink.c:1892 > sock_sendmsg_nosec net/socket.c:652 [inline] > sock_sendmsg net/socket.c:672 [inline] > ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343 > ___sys_sendmsg net/socket.c:2397 [inline] > __sys_sendmsg+0x451/0x5f0 net/socket.c:2430 > __compat_sys_sendmsg net/compat.c:642 [inline] > __do_compat_sys_sendmsg net/compat.c:649 [inline] > __se_compat_sys_sendmsg net/compat.c:646 [inline] > __ia32_compat_sys_sendmsg+0xed/0x130 net/compat.c:646 > do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline] > do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410 > entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139 > =====================================================
I found and fixed this while fixing the other audit uninit var problem found by syzbot. -- paul moore www.paul-moore.com -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit