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AJvYcCUd7A/eB//UVK7WH+iD6VxCrkPI5WsR+IL+n0NP0F365Z5yiIi2zK3V2nNFO48LtC7+eMt55iM4VLNVELE=@vger.kernel.org X-Gm-Message-State: AOJu0Yw3cIqf2KRcyypB+FwdmrgE3Rz+dGCH26rz78mxXznXo4REad6G RkZG+OQwe7UZHxV/txLS+DhrS46lkOfYg/F8S2CdsagqS2/MgsABS6N/BjleE+hqiFD938UTOZZ yvs0eIxE1t3g8Utbp7Td493A8RigcUperk1s3xdroEeMhKhYO+Vf0MoM7Yp8= X-Google-Smtp-Source: AGHT+IGvyH8CEXkBdFB4JzNpK1eelslDd70ahqIzqsAsyfrB7/61m+XVa9JJzCXVfbtFj/GufI4EK3lcDtQMekVqphL7gFye/f0j Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:220b:b0:433:2dbd:e93c with SMTP id e9e14a558f8ab-435b8e3d746mr205040265ab.4.1764279747289; Thu, 27 Nov 2025 13:42:27 -0800 (PST) Date: Thu, 27 Nov 2025 13:42:27 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6928c5c3.a70a0220.d98e3.011a.GAE@google.com> Subject: [syzbot] [fs?] general protection fault in mntput From: syzbot To: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 92fd6e84175b Add linux-next specific files for 20251125 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=13a55612580000 kernel config: https://syzkaller.appspot.com/x/.config?x=bf77a4e0e3514deb dashboard link: https://syzkaller.appspot.com/bug?extid=94048264da5715c251f9 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1215f612580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17082f42580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/bee2604d495b/disk-92fd6e84.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b12aade49e2c/vmlinux-92fd6e84.xz kernel image: https://storage.googleapis.com/syzbot-assets/286fd34158cb/bzImage-92fd6e84.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+94048264da5715c251f9@syzkaller.appspotmail.com Oops: general protection fault, probably for non-canonical address 0xdffffc0000000023: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f] CPU: 0 UID: 0 PID: 6414 Comm: syz.3.69 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:mntput+0x31/0xc0 fs/namespace.c:1430 Code: 41 56 41 54 53 48 89 fb e8 1c da 7e ff 48 85 db 74 47 49 bf 00 00 00 00 00 fc ff df 4c 8d b3 24 01 00 00 4d 89 f4 49 c1 ec 03 <43> 0f b6 04 3c 84 c0 75 50 48 83 c3 e0 41 8b 2e 31 ff 89 ee e8 26 RSP: 0018:ffffc9000462fd90 EFLAGS: 00010202 RAX: ffffffff8242c664 RBX: fffffffffffffff4 RCX: ffff888077aa5b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: fffffffffffffff4 RBP: ffffc9000462fed0 R08: ffff888077aa5b87 R09: 1ffff1100ef54b70 R10: dffffc0000000000 R11: ffffed100ef54b71 R12: 0000000000000023 R13: dffffc0000000000 R14: 0000000000000118 R15: dffffc0000000000 FS: 00007fdf2c77f6c0(0000) GS:ffff888125e8b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555575df7808 CR3: 0000000076002000 CR4: 00000000003526f0 Call Trace: __do_sys_fsmount fs/namespace.c:4380 [inline] __se_sys_fsmount+0x893/0xa90 fs/namespace.c:4279 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdf2b98f749 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:00007fdf2c77f038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b0 RAX: ffffffffffffffda RBX: 00007fdf2bbe6180 RCX: 00007fdf2b98f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fdf2ba13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdf2bbe6218 R14: 00007fdf2bbe6180 R15: 00007ffd8048bbc8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:mntput+0x31/0xc0 fs/namespace.c:1430 Code: 41 56 41 54 53 48 89 fb e8 1c da 7e ff 48 85 db 74 47 49 bf 00 00 00 00 00 fc ff df 4c 8d b3 24 01 00 00 4d 89 f4 49 c1 ec 03 <43> 0f b6 04 3c 84 c0 75 50 48 83 c3 e0 41 8b 2e 31 ff 89 ee e8 26 RSP: 0018:ffffc9000462fd90 EFLAGS: 00010202 RAX: ffffffff8242c664 RBX: fffffffffffffff4 RCX: ffff888077aa5b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: fffffffffffffff4 RBP: ffffc9000462fed0 R08: ffff888077aa5b87 R09: 1ffff1100ef54b70 R10: dffffc0000000000 R11: ffffed100ef54b71 R12: 0000000000000023 R13: dffffc0000000000 R14: 0000000000000118 R15: dffffc0000000000 FS: 00007fdf2c77f6c0(0000) GS:ffff888125f8b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd4a51d5e8 CR3: 0000000076002000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: 41 56 push %r14 2: 41 54 push %r12 4: 53 push %rbx 5: 48 89 fb mov %rdi,%rbx 8: e8 1c da 7e ff call 0xff7eda29 d: 48 85 db test %rbx,%rbx 10: 74 47 je 0x59 12: 49 bf 00 00 00 00 00 movabs $0xdffffc0000000000,%r15 19: fc ff df 1c: 4c 8d b3 24 01 00 00 lea 0x124(%rbx),%r14 23: 4d 89 f4 mov %r14,%r12 26: 49 c1 ec 03 shr $0x3,%r12 * 2a: 43 0f b6 04 3c movzbl (%r12,%r15,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 50 jne 0x83 33: 48 83 c3 e0 add $0xffffffffffffffe0,%rbx 37: 41 8b 2e mov (%r14),%ebp 3a: 31 ff xor %edi,%edi 3c: 89 ee mov %ebp,%esi 3e: e8 .byte 0xe8 3f: 26 es --- 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 report is already addressed, 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 report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup