Re: WARNING in idr_destroy

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered crash:
WARNING in idr_destroy

RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000203 R14: 00000000004c3e56 R15: 0000000000000008
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9124 at lib/radix-tree.c:682 radix_tree_free_nodes lib/radix-tree.c:682 [inline]
WARNING: CPU: 0 PID: 9124 at lib/radix-tree.c:682 idr_destroy+0x1ae/0x260 lib/radix-tree.c:1572
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9124 Comm: syz-executor.0 Not tainted 5.6.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 panic+0x264/0x7a9 kernel/panic.c:221
 __warn+0x209/0x210 kernel/panic.c:582
 report_bug+0x1b6/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0xcf/0x1c0 arch/x86/kernel/traps.c:267
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:radix_tree_free_nodes lib/radix-tree.c:682 [inline]
RIP: 0010:idr_destroy+0x1ae/0x260 lib/radix-tree.c:1572
Code: 43 5f f9 48 89 df 48 c7 c6 10 83 17 88 e8 ca 5c 4c f9 4c 3b 65 b8 74 57 e8 7f 43 5f f9 4d 89 fc e9 67 ff ff ff e8 72 43 5f f9 <0f> 0b eb d5 89 f9 80 e1 07 38 c1 7c 84 e8 e0 75 9c f9 e9 7a ff ff
RSP: 0018:ffffc900021b7ba0 EFLAGS: 00010293
RAX: ffffffff8817dc0e RBX: ffff8880aa010598 RCX: ffff888096740440
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff8880aa010588
RBP: ffffc900021b7be8 R08: ffffffff8817db80 R09: ffffed1011809f91
R10: ffffed1011809f91 R11: 0000000000000000 R12: ffff8880aa010580
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
 drm_mode_create_lease_ioctl+0x13c9/0x18c0 drivers/gpu/drm/drm_lease.c:587
 drm_ioctl_kernel+0x2cf/0x410 drivers/gpu/drm/drm_ioctl.c:786
 drm_ioctl+0x52f/0x890 drivers/gpu/drm/drm_ioctl.c:886
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c479
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f680fc16c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f680fc176d4 RCX: 000000000045c479
RDX: 0000000020000040 RSI: ffffffffffffffc6 RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000203 R14: 00000000004c3e56 R15: 0000000000000008
Kernel Offset: disabled
Rebooting in 86400 seconds..


Tested on:

commit:         7f398516 drm/lease: fix stack variable uninitialized
git tree:       https://github.com/hqj/hqjagain_test.git drm
console output: https://syzkaller.appspot.com/x/log.txt?x=1227a1f9e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cec95cb58b6f6294
dashboard link: https://syzkaller.appspot.com/bug?extid=05835159fe322770fe3d
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)