Hello,
syzbot found the following crash on:
HEAD commit: 6409e7e0 BACKPORT: dm bufio: introduce a global cache repl..
git tree: android-4.14
console output:
https://syzkaller.appspot.com/x/log.txt?x=16b19534e00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=15a2768a52194c6c
dashboard link:
https://syzkaller.appspot.com/bug?extid=401108efb50b91e7df72
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+401108...@syzkaller.appspotmail.com
audit: type=1400 audit(1572769945.483:26): avc: denied { syslog } for
pid=4239 comm="syz-executor.0" capability=34
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=capability2
permissive=1
=============================
WARNING: suspicious RCU usage
4.14.151+ #0 Not tainted
-----------------------------
./include/linux/radix-tree.h:238 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor.2/4237:
#0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000000a0b8d21>]
inode_lock include/linux/fs.h:724 [inline]
#0: (&sb->s_type->i_mutex_key#10){+.+.}, at: [<000000000a0b8d21>]
shmem_add_seals+0x12b/0xf80 mm/shmem.c:2831
#1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000f5cff072>]
spin_lock_irq include/linux/spinlock.h:342 [inline]
#1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000f5cff072>]
shmem_tag_pins mm/shmem.c:2685 [inline]
#1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000f5cff072>]
shmem_wait_for_pins mm/shmem.c:2726 [inline]
#1: (&(&mapping->tree_lock)->rlock){-.-.}, at: [<00000000f5cff072>]
shmem_add_seals+0x2e1/0xf80 mm/shmem.c:2843
stack backtrace:
CPU: 0 PID: 4237 Comm: syz-executor.2 Not tainted 4.14.151+ #0
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xca/0x134 lib/dump_stack.c:53
shmem_fcntl+0xea/0x120 mm/shmem.c:2878
do_fcntl+0x5c8/0xd20 fs/fcntl.c:421
SYSC_fcntl fs/fcntl.c:463 [inline]
SyS_fcntl+0xc6/0x100 fs/fcntl.c:448
do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459f49
RSP: 002b:00007fda0173cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000048
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459f49
RDX: 0000000000000009 RSI: 0000000000000409 RDI: 0000000000000006
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fda0173d6d4
R13: 00000000004c0904 R14: 00000000004d31f0 R15: 00000000ffffffff
audit: type=1400 audit(1572769945.523:27): avc: denied { map } for
pid=4249 comm="syz-executor.0"
path="/root/syzkaller-testdir784551788/syzkaller.EfL6PQ/7/file0/bus"
dev="ramfs" ino=10520
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=system_u:object_r:ramfs_t:s0 tclass=file permissive=1
audit: type=1400 audit(1572769945.753:28): avc: denied { map } for
pid=4267 comm="syz-executor.4" path="/dev/loop0" dev="devtmpfs" ino=1059
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=system_u:object_r:fixed_disk_device_t:s0 tclass=blk_file
permissive=1
netlink: 188 bytes leftover after parsing attributes in process
`syz-executor.1'.
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0
sclass=netlink_route_socket pig=4313 comm=syz-executor.1
input: syz1 as /devices/virtual/input/input11
input: syz1 as /devices/virtual/input/input12
audit: type=1400 audit(1572769948.313:29): avc: denied { create } for
pid=4419 comm="syz-executor.0"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
audit: type=1400 audit(1572769948.353:30): avc: denied { sys_admin } for
pid=4419 comm="syz-executor.0" capability=21
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns
permissive=1
audit: type=1400 audit(1572769948.723:31): avc: denied { dac_override }
for pid=4429 comm="syz-executor.0" capability=1
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns
permissive=1
audit: type=1400 audit(1572769949.123:32): avc: denied { mac_admin } for
pid=4437 comm="syz-executor.4" capability=33
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=capability2
permissive=1
SELinux: Context unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 is not
valid (left unmapped).
loop3: p1 < > p4
loop3: p1 size 2 extends beyond EOD, truncated
loop3: p4 start 1854537728 is beyond EOD, truncated
loop3: p1 < > p4
loop3: p1 size 2 extends beyond EOD, truncated
loop3: p4 start 1854537728 is beyond EOD, truncated
audit: type=1400 audit(1572769950.153:33): avc: denied { dyntransition }
for pid=4515 comm="syz-executor.1"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0 tclass=process permissive=1
input: syz1 as /devices/virtual/input/input13
audit: type=1400 audit(1572769950.683:34): avc: denied { dyntransition }
for pid=4515 comm="syz-executor.1"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0 tclass=process permissive=1
input: syz1 as /devices/virtual/input/input14
audit: type=1400 audit(1572769952.263:35): avc: denied { ioctl } for
pid=4548 comm="syz-executor.4" path="socket:[11983]" dev="sockfs" ino=11983
ioctlcmd=0x8946 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_generic_socket permissive=1
selinux_nlmsg_perm: 853 callbacks suppressed
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=21549
sclass=netlink_tcpdiag_socket pig=4744 comm=syz-executor.4
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=21549
sclass=netlink_tcpdiag_socket pig=4744 comm=syz-executor.4
SELinux: unrecognized netlink message: protocol=4 nlmsg_type=21549
sclass=netlink_tcpdiag_socket pig=4760 comm=syz-executor.4
audit: type=1400 audit(1572769954.253:36): avc: denied { getattr } for
pid=4787 comm="syz-executor.0" path="socket:[12131]" dev="sockfs" ino=12131
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_generic_socket permissive=1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=18873
sclass=netlink_route_socket pig=4783 comm=syz-executor.5
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=18873
sclass=netlink_route_socket pig=4783 comm=syz-executor.5
---
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