Hello, syzbot found the following issue on: HEAD commit: a12978712d90 selftests/bpf: Move ARRAY_SIZE to bpf_misc.h git tree: bpf-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=130457fa980000 kernel config: https://syzkaller.appspot.com/x/.config?x=736daf12bd72e034 dashboard link: https://syzkaller.appspot.com/bug?extid=16b6ab88e66b34d09014 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=125718be980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14528876980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9d845a55bf58/disk-a1297871.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/12cb27bdb2de/vmlinux-a1297871.xz kernel image: https://storage.googleapis.com/syzbot-assets/db09a1fa448c/bzImage-a1297871.xz The issue was bisected to: commit 21c38a3bd4ee3fb7337d013a638302fb5e5f9dc2 Author: Jesper Dangaard Brouer <hawk@xxxxxxxxxx> Date: Wed May 1 14:04:11 2024 +0000 cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14ecc085980000 final oops: https://syzkaller.appspot.com/x/report.txt?x=16ecc085980000 console output: https://syzkaller.appspot.com/x/log.txt?x=12ecc085980000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+16b6ab88e66b34d09014@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 21c38a3bd4ee ("cgroup/rstat: add cgroup_rstat_cpu_lock helpers and tracepoints") ============================================ WARNING: possible recursive locking detected 6.10.0-rc2-syzkaller-00797-ga12978712d90 #0 Not tainted -------------------------------------------- syz-executor646/5097 is trying to acquire lock: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_released+0x83/0x620 mm/mmap_lock.c:243 but task is already holding lock: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_released+0x83/0x620 mm/mmap_lock.c:243 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(lock#9); lock(lock#9); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor646/5097: #0: ffff8880182eb118 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:144 [inline] #0: ffff8880182eb118 (&mm->mmap_lock){++++}-{3:3}, at: acct_collect+0x1cf/0x830 kernel/acct.c:563 #1: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline] #1: ffff8880b94387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_released+0x83/0x620 mm/mmap_lock.c:243 #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline] #2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209 #3: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xbc/0x8a0 #4: ffff8880182eb118 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #4: ffff8880182eb118 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x237/0x9d0 kernel/bpf/stackmap.c:141 stack backtrace: CPU: 0 PID: 5097 Comm: syz-executor646 Not tainted 6.10.0-rc2-syzkaller-00797-ga12978712d90 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain+0x15d3/0x5900 kernel/locking/lockdep.c:3856 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] __mmap_lock_do_trace_released+0x9c/0x620 mm/mmap_lock.c:243 __mmap_lock_trace_released include/linux/mmap_lock.h:42 [inline] mmap_read_unlock include/linux/mmap_lock.h:170 [inline] bpf_mmap_unlock_mm kernel/bpf/mmap_unlock_work.h:52 [inline] stack_map_get_build_id_offset+0x9c7/0x9d0 kernel/bpf/stackmap.c:173 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449 bpf_prog_e6cf5f9c69743609+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] bpf_prog_run_array include/linux/bpf.h:2104 [inline] trace_call_bpf+0x369/0x8a0 kernel/trace/bpf_trace.c:147 perf_trace_run_bpf_submit+0x7c/0x1d0 kernel/events/core.c:10269 perf_trace_mmap_lock+0x3d7/0x510 include/trace/events/mmap_lock.h:16 trace_mmap_lock_released include/trace/events/mmap_lock.h:50 [inline] __mmap_lock_do_trace_released+0x5bb/0x620 mm/mmap_lock.c:243 __mmap_lock_trace_released include/linux/mmap_lock.h:42 [inline] mmap_read_unlock include/linux/mmap_lock.h:170 [inline] acct_collect+0x81d/0x830 kernel/acct.c:566 do_exit+0x936/0x27e0 kernel/exit.c:853 do_group_exit+0x207/0x2c0 kernel/exit.c:1023 __do_sys_exit_group kernel/exit.c:1034 [inline] __se_sys_exit_group kernel/exit.c:1032 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1032 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8fac26d039 Code: 90 49 c7 c0 b8 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00 RSP: 002b:00007ffd95d56e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8fac26d039 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007f8fac2e82b0 R08: ffffffffffffffb8 R09: 00000000000000a0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8fac2e82b0 R13: 0000000000000000 R14: 00007f8fac2e8d20 R15: 00007f8fac23e1e0 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup