syzbot


KMSAN: uninit-value in __fget_light (2)

Status: fixed on 2020/11/16 12:12
Subsystems: fs
[Documentation on labels]
Fix commit: d5e4d0a5e692 inet_diag: validate INET_DIAG_REQ_PROTOCOL attribute
First crash: 1430d, last: 1325d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in __fget_light fs 1 2247d 2247d 0/27 closed as invalid on 2018/06/27 15:08
upstream KASAN: null-ptr-deref Read in __fget_light fs 4 1110d 1204d 0/27 auto-closed as invalid on 2021/09/30 22:37

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in __fcheck_files include/linux/fdtable.h:86 [inline]
BUG: KMSAN: uninit-value in __fget_light+0x5de/0x6d0 fs/file.c:796
CPU: 1 PID: 8469 Comm: syz-executor080 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
 __fcheck_files include/linux/fdtable.h:86 [inline]
 __fget_light+0x5de/0x6d0 fs/file.c:796
 __fdget+0x4e/0x60 fs/file.c:809
 fdget include/linux/file.h:64 [inline]
 bpf_map_get+0x47/0x2b0 kernel/bpf/syscall.c:926
 bpf_sk_storage_diag_alloc+0x49a/0xb50 net/core/bpf_sk_storage.c:1002
 __inet_diag_dump_start+0x68c/0x11f0 net/ipv4/inet_diag.c:1169
 inet_diag_dump_start_compat+0x4d/0x60 net/ipv4/inet_diag.c:1188
 __netlink_dump_start+0x633/0xd00 net/netlink/af_netlink.c:2343
 netlink_dump_start include/linux/netlink.h:246 [inline]
 inet_diag_rcv_msg_compat+0x5c1/0x940 net/ipv4/inet_diag.c:1258
 sock_diag_rcv_msg+0x211/0x610 net/core/sock_diag.c:256
 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469
 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:275
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
 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_sendmsg+0x623/0x750 net/socket.c:2439
 __compat_sys_sendmsg net/compat.c:466 [inline]
 __do_compat_sys_sendmsg net/compat.c:473 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:470
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:470
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f1e549
Code: Bad RIP value.
RSP: 002b:00000000ffb2847c EFLAGS: 00000246 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000000
RDX: 0000000000000000 RSI: 00000000080ea078 RDI: 00000000ffb284d0
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:80
 slab_alloc_node mm/slub.c:2839 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4478
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1083 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1175 [inline]
 netlink_sendmsg+0x7d3/0x14d0 net/netlink/af_netlink.c:1893
 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_sendmsg+0x623/0x750 net/socket.c:2439
 __compat_sys_sendmsg net/compat.c:466 [inline]
 __do_compat_sys_sendmsg net/compat.c:473 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:470
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:470
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
=====================================================

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/04 08:42 https://github.com/google/kmsan.git master 93f54a72361a 196277c4 .config console log report syz C ci-upstream-kmsan-gce-386
2020/07/17 07:38 https://github.com/google/kmsan.git master f0d5ec902b23 54b3c45e .config console log report syz C ci-upstream-kmsan-gce-386
2020/10/30 18:03 https://github.com/google/kmsan.git master e16174226146 a6e3ac3b .config console log report info ci-upstream-kmsan-gce-386
2020/10/18 18:45 https://github.com/google/kmsan.git master e67f4ba870c2 fea47c01 .config console log report info ci-upstream-kmsan-gce-386
2020/10/18 18:37 https://github.com/google/kmsan.git master e67f4ba870c2 fea47c01 .config console log report info ci-upstream-kmsan-gce-386
2020/10/10 00:30 https://github.com/google/kmsan.git master 5edb1df295b9 d81b165e .config console log report info ci-upstream-kmsan-gce-386
2020/10/04 22:03 https://github.com/google/kmsan.git master 5edb1df295b9 5ef9c291 .config console log report info ci-upstream-kmsan-gce-386
2020/09/29 19:22 https://github.com/google/kmsan.git master 5edb1df295b9 1b88c6d5 .config console log report info ci-upstream-kmsan-gce-386
2020/09/21 23:32 https://github.com/google/kmsan.git master c5a13b33ec11 9e1fa68e .config console log report info ci-upstream-kmsan-gce-386
2020/09/21 23:32 https://github.com/google/kmsan.git master c5a13b33ec11 9e1fa68e .config console log report info ci-upstream-kmsan-gce-386
2020/09/21 23:27 https://github.com/google/kmsan.git master c5a13b33ec11 9e1fa68e .config console log report info ci-upstream-kmsan-gce-386
2020/09/12 07:51 https://github.com/google/kmsan.git master 3b3ea6028136 79fb24e2 .config console log report ci-upstream-kmsan-gce-386
2020/09/04 08:21 https://github.com/google/kmsan.git master 3b3ea6028136 abf9ba4f .config console log report ci-upstream-kmsan-gce-386
2020/09/03 07:00 https://github.com/google/kmsan.git master 3b3ea6028136 abf9ba4f .config console log report ci-upstream-kmsan-gce-386
2020/08/27 20:51 https://github.com/google/kmsan.git master ce8056d1f79e 816e0689 .config console log report ci-upstream-kmsan-gce-386
2020/08/04 09:59 https://github.com/google/kmsan.git master 93f54a72361a 196277c4 .config console log report ci-upstream-kmsan-gce-386
2020/07/17 07:46 https://github.com/google/kmsan.git master f0d5ec902b23 54b3c45e .config console log report ci-upstream-kmsan-gce-386
2020/07/17 07:05 https://github.com/google/kmsan.git master f0d5ec902b23 54b3c45e .config console log report ci-upstream-kmsan-gce-386
* Struck through repros no longer work on HEAD.