Hello, syzbot hit the following crash on bpf-next commit b2fe5fa68642860e7de76167c3111623aa0d5de1 (Wed Jan 31 22:31:10 2018 +0000) Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next So far this crash happened 1575 times on bpf-next. C reproducer is attached. syzkaller reproducer is attached. Raw console output is attached. compiler: gcc (GCC) 7.1.1 20170620 .config is attached. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+7dbcd2d3b85f9b608b23@syzkaller.appspotmail.com It will help syzbot understand when the bug is fixed. See footer for details. If you forward the report, please keep this part and the footer. audit: type=1400 audit(1517546098.866:9): avc: denied { prog_run } for pid=4159 comm="syzkaller076311" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf permissive=1 ============================= WARNING: suspicious RCU usage 4.15.0+ #10 Not tainted ----------------------------- ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syzkaller076311/4159: #0: (&ctx->mutex){+.+.}, at: [<0000000027c8872d>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1253 #1: (bpf_event_mutex){+.+.}, at: [<0000000092294d8c>] perf_event_query_prog_array+0x10e/0x280 kernel/trace/bpf_trace.c:876 #2: (rcu_read_lock){....}, at: [<000000002b518ca0>] bpf_prog_array_copy_to_user+0x0/0x4d0 kernel/bpf/core.c:1568 stack backtrace: CPU: 0 PID: 4159 Comm: syzkaller076311 Not tainted 4.15.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592 rcu_preempt_sleep_check include/linux/rcupdate.h:301 [inline] ___might_sleep+0x385/0x470 kernel/sched/core.c:6079 __might_sleep+0x95/0x190 kernel/sched/core.c:6067 __might_fault+0xab/0x1d0 mm/memory.c:4532 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] bpf_prog_array_copy_to_user+0x217/0x4d0 kernel/bpf/core.c:1587 bpf_prog_array_copy_info+0x17b/0x1c0 kernel/bpf/core.c:1685 perf_event_query_prog_array+0x196/0x280 kernel/trace/bpf_trace.c:877 _perf_ioctl kernel/events/core.c:4737 [inline] perf_ioctl+0x3e1/0x1480 kernel/events/core.c:4757 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x43ffd9 RSP: 002b:00007ffde8594aa8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 000000000043ffd9 RDX: 0000000020a40000 RSI: 00000000c008240a RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401900 R13: 0000000000401990 R14: 0000000000000000 R15: 0000000000000000 BUG: sleeping function called from invalid context at lib/usercopy.c:25 in_atomic(): 1, irqs_disabled(): 0, pid: 4159, name: syzkaller076311 3 locks held by syzkaller076311/4159: #0: (&ctx->mutex){+.+.}, at: [<0000000027c8872d>] perf_event_ctx_lock_nested+0x21b/0x450 kernel/events/core.c:1253 #1: (bpf_event_mutex){+.+.}, at: [<0000000092294d8c>] perf_event_query_prog_array+0x10e/0x280 kernel/trace/bpf_trace.c:876 #2: (rcu_read_lock){....}, at: [<000000002b518ca0>] bpf_prog_array_copy_to_user+0x0/0x4d0 kernel/bpf/core.c:1568 CPU: 0 PID: 4159 Comm: syzkaller076311 Not tainted 4.15.0+ #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6114 __might_sleep+0x95/0x190 kernel/sched/core.c:6067 __might_fault+0xab/0x1d0 mm/memory.c:4532 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] bpf_prog_array_copy_to_user+0x217/0x4d0 kernel/bpf/core.c:1587 bpf_prog_array_copy_info+0x17b/0x1c0 kernel/bpf/core.c:1685 perf_event_query_prog_array+0x196/0x280 kernel/trace/bpf_trace.c:877 _perf_ioctl kernel/events/core.c:4737 [inline] perf_ioctl+0x3e1/0x1480 kernel/events/core.c:4757 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x43ffd9 RSP: 002b:00007ffde8594aa8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 000000000043ffd9 RDX: 0000000020a40000 RSI: 00000000c008240a RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000 --- This bug is generated by a dumb bot. 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