================================================================== 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+0x1e3/0x4a0 block/genhd.c:206 Read of size 8 at addr ffff88801a42dc28 by task syz-executor.0/12197 CPU: 1 PID: 12197 Comm: syz-executor.0 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+0x176/0x24e lib/dump_stack.c:120 print_address_description+0x5f/0x3a0 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report+0x15c/0x200 mm/kasan/report.c:416 bdev_nr_sectors include/linux/genhd.h:266 [inline] disk_part_iter_next+0x1e3/0x4a0 block/genhd.c:206 blk_drop_partitions+0xab/0x250 block/partitions/core.c:541 bdev_disk_changed+0x128/0x3c0 fs/block_dev.c:1246 __loop_clr_fd+0x7a8/0xa20 drivers/block/loop.c:1271 loop_clr_fd drivers/block/loop.c:1336 [inline] lo_ioctl+0x103d/0x20b0 drivers/block/loop.c:1694 blkdev_ioctl+0x2e1/0x600 block/ioctl.c:583 block_ioctl+0xae/0xf0 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466217 Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 48 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7cc9201ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7cc9201f40 RCX: 0000000000466217 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f7cc92026bc R08: 0000000000000001 R09: 00007f7cc9201d90 R10: 00007f7cc9201c47 R11: 0000000000000246 R12: 0000000000000008 R13: 0000000000000000 R14: 0000000000000000 R15: 00007f7cc9201f80 Allocated by task 10058: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] __kasan_slab_alloc+0x8f/0xc0 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_node mm/slub.c:2907 [inline] slab_alloc mm/slub.c:2915 [inline] kmem_cache_alloc+0x1c3/0x350 mm/slub.c:2920 bdev_alloc_inode+0x17/0x80 fs/block_dev.c:795 alloc_inode fs/inode.c:234 [inline] new_inode_pseudo+0x61/0x220 fs/inode.c:928 new_inode+0x25/0x1d0 fs/inode.c:957 bdev_alloc+0x20/0x290 fs/block_dev.c:885 add_partition+0x13c/0x790 block/partitions/core.c:346 bdev_add_partition+0x1a8/0x1f0 block/partitions/core.c:449 blkpg_do_ioctl+0x29d/0x300 block/ioctl.c:43 blkpg_ioctl block/ioctl.c:60 [inline] blkdev_ioctl+0x36d/0x600 block/ioctl.c:548 block_ioctl+0xae/0xf0 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 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 12202: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:357 ____kasan_slab_free+0x100/0x140 mm/kasan/common.c:360 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x171/0x270 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kmem_cache_free+0x85/0x170 mm/slub.c:3177 rcu_do_batch kernel/rcu/tree.c:2559 [inline] rcu_core+0x858/0x1360 kernel/rcu/tree.c:2794 __do_softirq+0x318/0x714 kernel/softirq.c:345 Last potentially related work creation: kasan_save_stack+0x27/0x50 mm/kasan/common.c:38 kasan_record_aux_stack+0xee/0x120 mm/kasan/generic.c:345 __call_rcu kernel/rcu/tree.c:3039 [inline] call_rcu+0x130/0x8e0 kernel/rcu/tree.c:3114 disk_part_iter_exit block/genhd.c:235 [inline] disk_part_iter_next+0x61/0x4a0 block/genhd.c:202 blk_drop_partitions+0x1c5/0x250 block/partitions/core.c:541 bdev_disk_changed+0x128/0x3c0 fs/block_dev.c:1246 loop_reread_partitions drivers/block/loop.c:655 [inline] loop_set_status+0xa2a/0xd00 drivers/block/loop.c:1418 lo_ioctl+0xb56/0x20b0 drivers/block/loop.c:1528 blkdev_ioctl+0x2e1/0x600 block/ioctl.c:583 block_ioctl+0xae/0xf0 fs/block_dev.c:1667 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 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 ffff88801a42dc00 which belongs to the cache bdev_cache of size 2792 The buggy address is located 40 bytes inside of 2792-byte region [ffff88801a42dc00, ffff88801a42e6e8) The buggy address belongs to the page: page:ffffea0000690a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801a42f300 pfn:0x1a428 head:ffffea0000690a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff8880109bdc80 raw: ffff88801a42f300 00000000800b000a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801a42db00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff88801a42db80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801a42dc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801a42dc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801a42dd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================