Re: [syzbot] [bpf?] WARNING: locking bug in bpf_map_put

[syzbot <syzbot+d2adb332fe371b0595e3@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: locking bug in bpf_map_put

=============================
[ BUG: Invalid wait context ]
6.12.0-rc5-syzkaller-00291-g05b92660cdfe #0 Not tainted
-----------------------------
syz.0.15/6647 is trying to lock:
ffffffff8e9b57d8 (map_idr_lock){+...}-{3:3}, at: bpf_map_free_id kernel/bpf/syscall.c:380 [inline]
ffffffff8e9b57d8 (map_idr_lock){+...}-{3:3}, at: bpf_map_put+0x9a/0x380 kernel/bpf/syscall.c:808
other info that might help us debug this:
context-{5:5}
2 locks held by syz.0.15/6647:
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:3}, at: map_delete_elem+0x338/0x5c0 kernel/bpf/syscall.c:1677
 #1: ffff88807caca0f8 (&htab->lockdep_key){....}-{2:2}, at: htab_lock_bucket+0x1a4/0x370 kernel/bpf/hashtab.c:167
stack backtrace:
CPU: 0 UID: 0 PID: 6647 Comm: syz.0.15 Not tainted 6.12.0-rc5-syzkaller-00291-g05b92660cdfe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4802 [inline]
 check_wait_context kernel/locking/lockdep.c:4874 [inline]
 __lock_acquire+0x15a8/0x2100 kernel/locking/lockdep.c:5152
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 bpf_map_free_id kernel/bpf/syscall.c:380 [inline]
 bpf_map_put+0x9a/0x380 kernel/bpf/syscall.c:808
 htab_put_fd_value kernel/bpf/hashtab.c:911 [inline]
 free_htab_elem+0xbb/0x460 kernel/bpf/hashtab.c:946
 htab_map_delete_elem+0x576/0x6b0 kernel/bpf/hashtab.c:1438
 map_delete_elem+0x431/0x5c0 kernel/bpf/syscall.c:1678
 __sys_bpf+0x598/0x810 kernel/bpf/syscall.c:5644
 __do_sys_bpf kernel/bpf/syscall.c:5760 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5758 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5758
 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: 0033:0x7ff3cef7e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3cfda7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ff3cf135f80 RCX: 00007ff3cef7e719
RDX: 0000000000000020 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00007ff3ceff132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff3cf135f80 R15: 00007ffd7e2203e8
 </TASK>


Tested on:

commit:         05b92660 Merge tag 'pci-v6.12-fixes-2' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=145a9630580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a6b0d046ffd0e9c1
dashboard link: https://syzkaller.appspot.com/bug?extid=d2adb332fe371b0595e3
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.