================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:827 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 Read of size 4 at addr ffff88812e37fec4 by task kworker/u4:0/8 CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:827 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:946 ext4_ext_map_blocks+0x207/0x61e0 fs/ext4/extents.c:4166 ext4_map_blocks+0x988/0x1b30 fs/ext4/inode.c:674 mpage_map_one_extent fs/ext4/inode.c:2421 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2474 [inline] ext4_writepages+0x123f/0x3090 fs/ext4/inode.c:2842 do_writepages+0x473/0x6c0 mm/page-writeback.c:2388 __writeback_single_inode+0xd5/0x9c0 fs/fs-writeback.c:1657 writeback_sb_inodes+0xa10/0x1610 fs/fs-writeback.c:1940 wb_writeback+0x40b/0x9d0 fs/fs-writeback.c:2116 wb_do_writeback fs/fs-writeback.c:2263 [inline] wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2304 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the page: page:ffffea0004b8dfc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12e37f flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004b8dfc8 ffffea0004b8dfc8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff88812e37fd80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812e37fe00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88812e37fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88812e37ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88812e37ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6085: inode #15: comm kworker/u4:0: mark_inode_dirty error EXT4-fs error (device loop2): ext4_read_block_bitmap_nowait:476: comm kworker/u4:0: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop5): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop5) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs error (device loop5): ext4_dirty_inode:6085: inode #15: comm kworker/u4:0: mark_inode_dirty error EXT4-fs error (device loop5): ext4_read_block_bitmap_nowait:476: comm kworker/u4:0: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop5): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop5) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs (loop5): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop5): This should not happen!! Data will be lost EXT4-fs (loop5): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop5): This should not happen!! Data will be lost IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready bridge0: port 1(bridge_slave_0) entered disabled state bridge0: port 2(bridge_slave_1) entered disabled state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready bridge0: port 1(bridge_slave_0) entered blocking state bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready bridge0: port 2(bridge_slave_1) entered blocking state bridge0: port 2(bridge_slave_1) entered forwarding state IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready EXT4-fs error (device loop6): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop6) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs error (device loop6): ext4_dirty_inode:6085: inode #15: comm kworker/u4:0: mark_inode_dirty error EXT4-fs error (device loop6): ext4_read_block_bitmap_nowait:476: comm kworker/u4:0: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop6): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop6) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop6): This should not happen!! Data will be lost EXT4-fs (loop6): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop6): This should not happen!! Data will be lost EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6085: inode #15: comm kworker/u4:0: mark_inode_dirty error EXT4-fs error (device loop2): ext4_read_block_bitmap_nowait:476: comm kworker/u4:0: Invalid block bitmap block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4358: comm kworker/u4:0: Invalid inode table block 8391460049216894068 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5881: Corrupt filesystem EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 1 with max blocks 3 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 16 with max blocks 1 with error 117 EXT4-fs (loop2): This should not happen!! Data will be lost