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AFNElJ+q9PxAvC5d3jFVAcQhBBT0BOpy4FTCphN0/qwdnR2EeWYEcizhD05YFZsorM6SF+787OVaViuDDPxdDtE=@vger.kernel.org X-Gm-Message-State: AOJu0YwiB5ha3lwg7iZxaQzRDzxSORQ/PE9lPTEPBBqlyaNQGKsCcC/u MTjDI5Cd23sTPLFpy2JVmuKFpDsm2Uxq06Red+hJikrywGIrELytLNpCO/3zJGE55wlcoQ0ZJVD Qkre9JUcpb6gOPn4AqoBu2s6/rk3FtreHmuV8xdjTFergrjLb9A8kOexJQFU= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:6708:b0:681:22fd:a571 with SMTP id 006d021491bc7-68be8ae219cmr7748882eaf.47.1776243002567; Wed, 15 Apr 2026 01:50:02 -0700 (PDT) Date: Wed, 15 Apr 2026 01:50:02 -0700 In-Reply-To: <20260415075013.1880-1-hdanton@sina.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69df513a.a00a0220.475f0.004c.GAE@google.com> Subject: Re: [syzbot] [dri?] KASAN: slab-use-after-free Read in drm_gem_object_release_handle From: syzbot To: hdanton@sina.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: possible deadlock in drm_gem_object_release_handle ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.2.19/6521 is trying to acquire lock: ffff88801d349388 (&prime_fpriv->lock){+.+.}-{4:4}, at: drm_gem_object_release_handle+0x98/0x1e0 drivers/gpu/drm/drm_gem.c:377 but task is already holding lock: ffff88801d349388 (&prime_fpriv->lock){+.+.}-{4:4}, at: drm_gem_release+0x90/0x190 drivers/gpu/drm/drm_gem.c:1087 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&prime_fpriv->lock); lock(&prime_fpriv->lock); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz.2.19/6521: #0: ffff88801d349388 (&prime_fpriv->lock){+.+.}-{4:4}, at: drm_gem_release+0x90/0x190 drivers/gpu/drm/drm_gem.c:1087 stack backtrace: CPU: 1 UID: 0 PID: 6521 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:632 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:806 drm_gem_object_release_handle+0x98/0x1e0 drivers/gpu/drm/drm_gem.c:377 drm_gem_release+0xe5/0x190 drivers/gpu/drm/drm_gem.c:1097 drm_file_free+0x729/0xa00 drivers/gpu/drm/drm_file.c:261 drm_close_helper drivers/gpu/drm/drm_file.c:290 [inline] drm_release+0x2de/0x3f0 drivers/gpu/drm/drm_file.c:438 __fput+0x44f/0xa60 fs/file_table.c:510 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f141259c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcebeea6c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ffcebeea7b0 RCX: 00007f141259c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 000000000001fd63 R08: 0000000000000001 R09: 0000000000000000 R10: 0000001b31120000 R11: 0000000000000246 R12: 00007ffcebeea7f0 R13: 00007f141281609c R14: 000000000001fdc6 R15: 00007f1412816090 Tested on: commit: 1f5ffc67 Fix mismerge of the arm64 / timer-core interr.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=145ebb16580000 kernel config: https://syzkaller.appspot.com/x/.config?x=95729ed00549063a dashboard link: https://syzkaller.appspot.com/bug?extid=b2e951687503f32f74ce compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 patch: https://syzkaller.appspot.com/x/patch.diff?x=150dfcd2580000