Re: [syzbot] [dri?] WARNING in drm_gem_object_handle_put_unlocked

[syzbot]

Hello,

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

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f37b0f9bf80 R15: 00007ffdb4a472f8
 </TASK>
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5572 at drivers/gpu/drm/drm_gem.c:225 drm_gem_object_handle_put_unlocked+0x299/0x390 drivers/gpu/drm/drm_gem.c:225
Modules linked in:
CPU: 1 PID: 5572 Comm: syz-executor.0 Not tainted 6.7.0-rc1-syzkaller-00019-gc42d9eeef8e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
RIP: 0010:drm_gem_object_handle_put_unlocked+0x299/0x390 drivers/gpu/drm/drm_gem.c:225
Code: ea 03 0f b6 04 02 84 c0 74 0c 3c 03 7f 08 4c 89 f7 e8 db 00 24 fd c7 83 20 01 00 00 00 00 00 00 e9 98 fe ff ff e8 87 2d cd fc <0f> 0b 5b 5d 41 5c 41 5d 41 5e e9 78 2d cd fc e8 73 2d cd fc 48 8d
RSP: 0018:ffffc90004f47bb8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880440f1800 RCX: ffffffff84bb752f
RDX: ffff88801f5fd940 RSI: ffffffff84bb7759 RDI: 0000000000000005
RBP: ffff8880440f1804 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88801c368000
R13: ffff8880440f1808 R14: 0000000000000000 R15: ffff8880440f1818
FS:  00007f37b1b6a6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37b1b69c98 CR3: 00000000286d0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_gem_handle_create_tail+0x32a/0x540 drivers/gpu/drm/drm_gem.c:407
 drm_gem_shmem_create_with_handle drivers/gpu/drm/drm_gem_shmem_helper.c:417 [inline]
 drm_gem_shmem_dumb_create+0x21a/0x310 drivers/gpu/drm/drm_gem_shmem_helper.c:505
 drm_mode_create_dumb drivers/gpu/drm/drm_dumb_buffers.c:96 [inline]
 drm_mode_create_dumb_ioctl+0x268/0x2f0 drivers/gpu/drm/drm_dumb_buffers.c:102
 drm_ioctl_kernel+0x28c/0x4d0 drivers/gpu/drm/drm_ioctl.c:792
 drm_ioctl+0x5cb/0xbf0 drivers/gpu/drm/drm_ioctl.c:895
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f37b0e7cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f37b1b6a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f37b0f9bf80 RCX: 00007f37b0e7cae9
RDX: 0000000020000080 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 00007f37b1b6a120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 000000000000000b R14: 00007f37b0f9bf80 R15: 00007ffdb4a472f8
 </TASK>


Tested on:

commit:         c42d9eee Merge tag 'hardening-v6.7-rc2' of git://git.k..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1304223f680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=54e2bd738b08eef2
dashboard link: https://syzkaller.appspot.com/bug?extid=ef3256a360c02207a4cb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.