================================================================== BUG: KASAN: use-after-free in bdev_nr_sectors include/linux/genhd.h:266 [inline] BUG: KASAN: use-after-free in disk_part_iter_next+0x49d/0x530 block/genhd.c:206 Read of size 8 at addr ffff888080773228 by task systemd-udevd/4836 CPU: 1 PID: 4836 Comm: systemd-udevd Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 bdev_nr_sectors include/linux/genhd.h:266 [inline] disk_part_iter_next+0x49d/0x530 block/genhd.c:206 blk_drop_partitions+0x10a/0x180 block/partitions/core.c:541 bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246 __blkdev_get+0x86c/0xa30 fs/block_dev.c:1350 blkdev_get_by_dev fs/block_dev.c:1454 [inline] blkdev_get_by_dev+0x26c/0x600 fs/block_dev.c:1422 blkdev_reread_part block/ioctl.c:100 [inline] blkdev_common_ioctl+0x137e/0x17e0 block/ioctl.c:508 blkdev_ioctl+0x1ef/0x6d0 block/ioctl.c:577 block_ioctl+0xf9/0x140 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4fd5cfc017 Code: 00 00 00 48 8b 05 81 7e 2b 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 7e 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe2f2db7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffe2f2db890 RCX: 00007f4fd5cfc017 RDX: 0000000000000000 RSI: 000000000000125f RDI: 000000000000000e RBP: 00007ffe2f2dbd00 R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe2f2db9a0 R13: 00005602b5e60a60 R14: 00005602b5f11e00 R15: 00007ffe2f2db870 Allocated by task 19337: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:460 kasan_slab_alloc include/linux/kasan.h:223 [inline] slab_post_alloc_hook mm/slab.h:516 [inline] slab_alloc mm/slab.c:3325 [inline] kmem_cache_alloc+0x1c8/0x500 mm/slab.c:3502 bdev_alloc_inode+0x18/0x80 fs/block_dev.c:795 alloc_inode+0x61/0x230 fs/inode.c:234 new_inode_pseudo fs/inode.c:928 [inline] new_inode+0x27/0x2f0 fs/inode.c:957 bdev_alloc+0x20/0x2f0 fs/block_dev.c:885 add_partition+0x1ab/0x880 block/partitions/core.c:346 bdev_add_partition+0xb6/0x130 block/partitions/core.c:449 blkpg_do_ioctl+0x2d0/0x340 block/ioctl.c:43 blkpg_ioctl block/ioctl.c:60 [inline] blkdev_ioctl+0x577/0x6d0 block/ioctl.c:548 block_ioctl+0xf9/0x140 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 274: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xc7/0x100 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] __cache_free mm/slab.c:3440 [inline] kmem_cache_free+0x6d/0x1f0 mm/slab.c:3733 i_callback+0x3f/0x70 fs/inode.c:223 rcu_do_batch kernel/rcu/tree.c:2559 [inline] rcu_core+0x74a/0x12f0 kernel/rcu/tree.c:2794 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345 __call_rcu kernel/rcu/tree.c:3039 [inline] call_rcu+0xb1/0x740 kernel/rcu/tree.c:3114 destroy_inode+0x129/0x1b0 fs/inode.c:289 iput_final fs/inode.c:1654 [inline] iput.part.0+0x57e/0x810 fs/inode.c:1680 iput+0x58/0x70 fs/inode.c:1670 disk_part_iter_exit block/genhd.c:235 [inline] disk_part_iter_next+0x9a/0x530 block/genhd.c:202 blk_drop_partitions+0x10a/0x180 block/partitions/core.c:541 bdev_disk_changed+0x238/0x430 fs/block_dev.c:1246 __blkdev_get+0x86c/0xa30 fs/block_dev.c:1350 blkdev_get_by_dev fs/block_dev.c:1454 [inline] blkdev_get_by_dev+0x26c/0x600 fs/block_dev.c:1422 blkdev_reread_part block/ioctl.c:100 [inline] blkdev_common_ioctl+0x137e/0x17e0 block/ioctl.c:508 blkdev_ioctl+0x1ef/0x6d0 block/ioctl.c:577 block_ioctl+0xf9/0x140 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888080773200 which belongs to the cache bdev_cache of size 2792 The buggy address is located 40 bytes inside of 2792-byte region [ffff888080773200, ffff888080773ce8) The buggy address belongs to the page: page:ffffea000201dcc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888080773fff pfn:0x80773 flags: 0xfff00000000200(slab) raw: 00fff00000000200 ffffea00005de588 ffffea0000d39488 ffff888010a9f700 raw: ffff888080773fff ffff888080773200 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888080773100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888080773180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888080773200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888080773280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888080773300: fb fb fb fb fb fb fb fb fb 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