syzbot has found a reproducer for the following issue on: HEAD commit: c0b832517f62 Add linux-next specific files for 20240402 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=14af7dd9180000 kernel config: https://syzkaller.appspot.com/x/.config?x=afcaf46d374cec8c dashboard link: https://syzkaller.appspot.com/bug?extid=7b219b86935220db6dd8 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1729f003180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17fa4341180000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/0d36ec76edc7/disk-c0b83251.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6f9bb4e37dd0/vmlinux-c0b83251.xz kernel image: https://storage.googleapis.com/syzbot-assets/2349287b14b7/bzImage-c0b83251.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/9760c52a227c/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7b219b86935220db6dd8@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff888020485fa8 by task kworker/u8:2/35 CPU: 0 PID: 35 Comm: kworker/u8:2 Not tainted 6.9.0-rc2-next-20240402-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 __lock_acquire+0x78/0x1fd0 kernel/locking/lockdep.c:5005 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] wb_writeback+0x66f/0xd30 fs/fs-writeback.c:2160 wb_check_old_data_flush fs/fs-writeback.c:2233 [inline] wb_do_writeback fs/fs-writeback.c:2286 [inline] wb_workfn+0xba1/0x1090 fs/fs-writeback.c:2314 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 </TASK> Allocated by task 5052: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4048 [inline] __kmalloc_noprof+0x200/0x410 mm/slub.c:4061 kmalloc_noprof include/linux/slab.h:664 [inline] tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822 security_inode_getattr+0xd8/0x130 security/security.c:2269 vfs_getattr+0x45/0x430 fs/stat.c:173 vfs_fstat fs/stat.c:198 [inline] vfs_fstatat+0xd6/0x190 fs/stat.c:300 __do_sys_newfstatat fs/stat.c:468 [inline] __se_sys_newfstatat fs/stat.c:462 [inline] __x64_sys_newfstatat+0x125/0x1b0 fs/stat.c:462 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a Freed by task 5052: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2180 [inline] slab_free mm/slub.c:4363 [inline] kfree+0x149/0x350 mm/slub.c:4484 tomoyo_realpath_from_path+0x5a9/0x5e0 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822 security_inode_getattr+0xd8/0x130 security/security.c:2269 vfs_getattr+0x45/0x430 fs/stat.c:173 vfs_fstat fs/stat.c:198 [inline] vfs_fstatat+0xd6/0x190 fs/stat.c:300 __do_sys_newfstatat fs/stat.c:468 [inline] __se_sys_newfstatat fs/stat.c:462 [inline] __x64_sys_newfstatat+0x125/0x1b0 fs/stat.c:462 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a The buggy address belongs to the object at ffff888020484000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 4008 bytes to the right of allocated 4096-byte region [ffff888020484000, ffff888020485000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20480 head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff80000000040(head|node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffefff(slab) raw: 00fff80000000040 ffff888015042140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001ffffefff 0000000000000000 head: 00fff80000000040 ffff888015042140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000001ffffefff 0000000000000000 head: 00fff80000000003 ffffea0000812001 ffffea0000812048 00000000ffffffff head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid -957297381 (swapper/0), ts 1, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490 prep_new_page mm/page_alloc.c:1498 [inline] get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline] alloc_pages_node_noprof include/linux/gfp.h:271 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2249 allocate_slab+0x5a/0x2e0 mm/slub.c:2412 new_slab mm/slub.c:2465 [inline] ___slab_alloc+0xea8/0x1430 mm/slub.c:3599 __slab_alloc+0x58/0xa0 mm/slub.c:3684 __slab_alloc_node mm/slub.c:3737 [inline] slab_alloc_node mm/slub.c:3915 [inline] kmalloc_node_trace_noprof+0x20c/0x300 mm/slub.c:4087 kmalloc_node_noprof include/linux/slab.h:677 [inline] bdi_alloc+0x4f/0x140 mm/backing-dev.c:894 __alloc_disk_node+0xb8/0x590 block/genhd.c:1347 __blk_mq_alloc_disk+0x17d/0x260 block/blk-mq.c:4166 loop_add+0x448/0xba0 drivers/block/loop.c:2032 loop_init+0x17a/0x230 drivers/block/loop.c:2275 do_one_initcall+0x248/0x880 init/main.c:1258 do_initcall_level+0x157/0x210 init/main.c:1320 do_initcalls+0x3f/0x80 init/main.c:1336 page_owner free stack trace missing Memory state around the buggy address: ffff888020485e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888020485f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888020485f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888020486000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888020486080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- 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.
