[syzbot] [dri?] WARNING in drm_gem_object_handle_put_unlocked

[syzbot] [dri?] WARNING in drm_gem_object_handle_put_unlocked

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    0bb80ecc33a8 Linux 6.6-rc1
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1002530c680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f4894cf58531f
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
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14a79ca0680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16900402680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eeb0cac260c7/disk-0bb80ecc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a3c360110254/vmlinux-0bb80ecc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/22b81065ba5f/bzImage-0bb80ecc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ef3256a360c02207a4cb@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 00007fda971e917c
R13: 00007fda97153210 R14: 0023647261632f69 R15: 6972642f7665642f
 </TASK>
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5043 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: 5043 Comm: syz-executor141 Not tainted 6.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
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 2b 06 2a fd c7 83 20 01 00 00 00 00 00 00 e9 98 fe ff ff e8 57 44 d4 fc <0f> 0b 5b 5d 41 5c 41 5d 41 5e e9 48 44 d4 fc e8 43 44 d4 fc 48 8d
RSP: 0018:ffffc90003d5fbb8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888027b61000 RCX: 0000000000000000
RDX: ffff888014fcbb80 RSI: ffffffff84b38a29 RDI: 0000000000000005
RBP: ffff888027b61004 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88801d140000
R13: ffff888027b61008 R14: 0000000000000000 R15: ffff888027b61018
FS:  00007fda971536c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda971fe794 CR3: 0000000072975000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drm_gem_handle_create_tail+0x32f/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+0x280/0x4c0 drivers/gpu/drm/drm_ioctl.c:789
 drm_ioctl+0x5cb/0xbf0 drivers/gpu/drm/drm_ioctl.c:892
 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:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fda971954e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 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:00007fda971531f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fda9721c3e8 RCX: 00007fda971954e9
RDX: 0000000020000080 RSI: 00000000c02064b2 RDI: 0000000000000003
RBP: 00007fda9721c3e0 R08: 00007fda97152f96 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fda971e917c
R13: 00007fda97153210 R14: 0023647261632f69 R15: 6972642f7665642f
 </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@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the bug is already fixed, 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 bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] Test

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Test
Author: mukattreyee@gmail.com

#syz test:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Re: [syzbot] [PATCH] Tried removing the warning.

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Tried removing the warning.
Author: tintinm2017@gmail.com

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Signed-off-by: attreyee-muk <tintinm2017@gmail.com>
---
 drivers/gpu/drm/drm_gem.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 44a948b80ee1..d4ff4e6850a1 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -222,9 +222,6 @@ drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
 	struct drm_device *dev = obj->dev;
 	bool final = false;
 
-	if (WARN_ON(READ_ONCE(obj->handle_count) == 0))
-		return;
-
 	/*
 	* Must bump handle count first as this may be the last
 	* ref, in which case the object would disappear before we
-- 
2.34.1

Re: [syzbot] [PATCH] Tried removing the error

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Tried removing the error
Author: tintinm2017@gmail.com

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Signed-off-by: attreyee-muk <tintinm2017@gmail.com>
---
 drivers/gpu/drm/drm_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 44a948b80ee1..b6be9400cd11 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -222,7 +222,7 @@ drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj)
 	struct drm_device *dev = obj->dev;
 	bool final = false;
 
-	if (WARN_ON(READ_ONCE(obj->handle_count) == 0))
+	if (READ_ONCE(obj->handle_count) == 0)
 		return;
 
 	/*
-- 
2.34.1