====================================================== WARNING: possible circular locking dependency detected 4.14.94+ #12 Not tainted ------------------------------------------------------ syz-executor1/881 is trying to acquire lock: (&sig->cred_guard_mutex){+.+.}, at: [] do_io_accounting+0x1da/0x790 fs/proc/base.c:2731 but task is already holding lock: (&p->lock){+.+.}, at: [] seq_read+0xcd/0x1180 fs/seq_file.c:165 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&p->lock){+.+.}: -> #1 (&pipe->mutex/1){+.+.}: -> #0 (&sig->cred_guard_mutex){+.+.}: other info that might help us debug this: Chain exists of: &sig->cred_guard_mutex --> &pipe->mutex/1 --> &p->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&p->lock); lock(&pipe->mutex/1); lock(&p->lock); lock(&sig->cred_guard_mutex); *** DEADLOCK *** 1 lock held by syz-executor1/881: #0: (&p->lock){+.+.}, at: [] seq_read+0xcd/0x1180 fs/seq_file.c:165 stack backtrace: CPU: 0 PID: 881 Comm: syz-executor1 Not tainted 4.14.94+ #12 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities kauditd_printk_skb: 270 callbacks suppressed audit: type=1400 audit(2000000015.340:38986): avc: denied { map } for pid=983 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.400:38987): avc: denied { map } for pid=983 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities audit: type=1400 audit(2000000015.400:38988): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.400:38989): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.440:38990): avc: denied { map } for pid=983 comm="blkid" path="/etc/ld.so.cache" dev="sda1" ino=2503 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.450:38991): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/libblkid.so.1.1.0" dev="sda1" ino=2825 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 EXT4-fs (loop2): couldn't mount as ext2 due to feature incompatibilities EXT4-fs (loop1): couldn't mount as ext2 due to feature incompatibilities audit: type=1400 audit(2000000015.460:38992): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/libblkid.so.1.1.0" dev="sda1" ino=2825 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.490:38993): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/libc-2.13.so" dev="sda1" ino=2784 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000015.500:38994): avc: denied { map } for pid=983 comm="blkid" path="/lib/x86_64-linux-gnu/libc-2.13.so" dev="sda1" ino=2784 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: audit_backlog=65 > audit_backlog_limit=64 EXT4-fs (loop2): couldn't mount as ext2 due to feature incompatibilities EXT4-fs (loop2): couldn't mount as ext2 due to feature incompatibilities kauditd_printk_skb: 414 callbacks suppressed audit: type=1400 audit(2000000020.350:39377): avc: denied { map } for pid=1119 comm="blkid" path="/lib/x86_64-linux-gnu/libuuid.so.1.3.0" dev="sda1" ino=2819 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.350:39378): avc: denied { map } for pid=1119 comm="blkid" path="/lib/x86_64-linux-gnu/libuuid.so.1.3.0" dev="sda1" ino=2819 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.880:39379): avc: denied { map } for pid=1137 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 EXT4-fs (loop1): VFS: Can't find ext4 filesystem audit: type=1400 audit(2000000020.910:39380): avc: denied { map } for pid=1137 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.930:39381): avc: denied { map } for pid=1137 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.930:39382): avc: denied { map } for pid=1137 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.950:39383): avc: denied { map } for pid=1141 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 EXT4-fs (loop1): VFS: Can't find ext4 filesystem audit: type=1400 audit(2000000020.950:39384): avc: denied { map } for pid=1141 comm="blkid" path="/sbin/blkid" dev="sda1" ino=16128 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(2000000020.950:39385): avc: denied { map } for pid=1141 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1