EXT4-fs (loop8): pa ffff88811c0369d8: logic 64, phys. 177, len 21 EXT4-fs error (device loop8): ext4_mb_release_inode_pa:4375: group 0, free 0, pa_free 1 ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:826 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 Read of size 4 at addr ffff888138e95018 by task syz.8.734/3019 CPU: 1 PID: 3019 Comm: syz.8.734 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_ext_binsearch fs/ext4/extents.c:826 [inline] ext4_find_extent+0xbeb/0xe20 fs/ext4/extents.c:945 ext4_ext_remove_space+0x2f0/0x4570 fs/ext4/extents.c:2829 ext4_collapse_range fs/ext4/extents.c:5429 [inline] ext4_fallocate+0x1006/0x1a70 fs/ext4/extents.c:4769 vfs_fallocate+0x4b4/0x590 fs/open.c:310 ksys_fallocate fs/open.c:333 [inline] __do_sys_fallocate fs/open.c:341 [inline] __se_sys_fallocate fs/open.c:339 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:339 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fcdec635819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcdeb06f028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fcdec8af090 RCX: 00007fcdec635819 RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000005 RBP: 00007fcdec6cbc91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcdec8af128 R14: 00007fcdec8af090 R15: 00007fff2a4e7b58 Allocated by task 296: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965 mempool_alloc_slab+0x1d/0x30 mm/mempool.c:513 mempool_alloc+0x11e/0x460 mm/mempool.c:393 bvec_alloc+0x13f/0x180 block/bio.c:208 bio_alloc_bioset+0x32c/0x570 block/bio.c:506 bio_alloc include/linux/bio.h:412 [inline] io_submit_init_bio fs/ext4/page-io.c:406 [inline] io_submit_add_bh fs/ext4/page-io.c:431 [inline] ext4_bio_write_page+0xd04/0x18b0 fs/ext4/page-io.c:567 mpage_submit_page+0x1cb/0x250 fs/ext4/inode.c:2157 mpage_map_and_submit_buffers fs/ext4/inode.c:2405 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2544 [inline] ext4_writepages+0x1a3d/0x2eb0 fs/ext4/inode.c:2873 do_writepages+0x128/0x280 mm/page-writeback.c:2380 __writeback_single_inode+0xd5/0xa20 fs/fs-writeback.c:1470 writeback_sb_inodes+0x8ca/0x1480 fs/fs-writeback.c:1733 __writeback_inodes_wb fs/fs-writeback.c:1804 [inline] wb_writeback+0x4bf/0xbe0 fs/fs-writeback.c:1910 wb_check_background_flush fs/fs-writeback.c:1978 [inline] wb_do_writeback fs/fs-writeback.c:2066 [inline] wb_workfn+0xb0a/0xf30 fs/fs-writeback.c:2094 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Freed by task 296: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kmem_cache_free+0x100/0x2d0 mm/slub.c:3224 mempool_free_slab+0x1d/0x30 mm/mempool.c:520 mempool_free+0xd8/0x340 mm/mempool.c:502 bvec_free block/bio.c:163 [inline] bio_free+0x1e4/0x360 block/bio.c:258 bio_put+0xbf/0x110 block/bio.c:-1 ext4_release_io_end+0xfa/0x2c0 fs/ext4/page-io.c:164 ext4_end_io_end fs/ext4/page-io.c:197 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:262 [inline] ext4_end_io_rsv_work+0x4f3/0x610 fs/ext4/page-io.c:276 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888138e94400 which belongs to the cache biovec-max of size 4096 The buggy address is located 3096 bytes inside of 4096-byte region [ffff888138e94400, ffff888138e95400) The buggy address belongs to the page: page:ffffea0004e3a400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x138e90 head:ffffea0004e3a400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888107fbe480 raw: 0000000000000000 0000000000070007 00000001ffffffff 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 0x1d2800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 296, ts 167156168564, free_ts 107302404437 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x1ac/0x2d0 mm/slub.c:2965 mempool_alloc_slab+0x1d/0x30 mm/mempool.c:513 mempool_alloc+0x11e/0x460 mm/mempool.c:393 bvec_alloc+0x13f/0x180 block/bio.c:208 bio_alloc_bioset+0x32c/0x570 block/bio.c:506 bio_alloc include/linux/bio.h:412 [inline] io_submit_init_bio fs/ext4/page-io.c:406 [inline] io_submit_add_bh fs/ext4/page-io.c:431 [inline] ext4_bio_write_page+0xd04/0x18b0 fs/ext4/page-io.c:567 mpage_submit_page+0x1cb/0x250 fs/ext4/inode.c:2157 mpage_map_and_submit_buffers fs/ext4/inode.c:2405 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2544 [inline] ext4_writepages+0x1a3d/0x2eb0 fs/ext4/inode.c:2873 do_writepages+0x128/0x280 mm/page-writeback.c:2380 __writeback_single_inode+0xd5/0xa20 fs/fs-writeback.c:1470 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5443 [inline] __free_pages+0x146/0x3b0 mm/page_alloc.c:5454 __vunmap+0x86d/0x9f0 mm/vmalloc.c:2307 __vfree mm/vmalloc.c:2356 [inline] vfree+0x61/0x90 mm/vmalloc.c:2387 htable_put+0x5fb/0x650 net/netfilter/xt_hashlimit.c:432 hashlimit_mt_destroy_v1+0x58/0x60 net/netfilter/xt_hashlimit.c:970 cleanup_match net/ipv4/netfilter/ip_tables.c:460 [inline] find_check_entry net/ipv4/netfilter/ip_tables.c:564 [inline] translate_table+0x1a53/0x20e0 net/ipv4/netfilter/ip_tables.c:717 do_replace net/ipv4/netfilter/ip_tables.c:1138 [inline] do_ipt_set_ctl+0x958/0xd70 net/ipv4/netfilter/ip_tables.c:1636 nf_setsockopt+0x272/0x2a0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0x28b1/0x3490 net/ipv4/ip_sockglue.c:1442 udp_setsockopt+0x8a/0xa0 net/ipv4/udp.c:2750 sock_common_setsockopt+0xa0/0xb0 net/core/sock.c:3327 __sys_setsockopt+0x2fa/0x480 net/socket.c:2146 __do_sys_setsockopt net/socket.c:2157 [inline] __se_sys_setsockopt net/socket.c:2154 [inline] __x64_sys_setsockopt+0xbf/0xd0 net/socket.c:2154 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888138e94f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888138e94f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888138e95000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888138e95080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888138e95100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ kernel BUG at fs/ext4/extents.c:3184! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3019 Comm: syz.8.734 Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:ext4_split_extent_at+0xe1f/0xe40 fs/ext4/extents.c:3184 Code: a7 cf d2 ff e9 05 fc ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 12 fc ff ff 48 89 df e8 6b cf d2 ff e9 05 fc ff ff e8 81 4f 98 ff <0f> 0b e8 7a 4f 98 ff 0f 0b e8 73 4f 98 ff 0f 0b e8 6c 4f 98 ff 0f RSP: 0018:ffffc90000c279e0 EFLAGS: 00010293 RAX: ffffffff81cc63cf RBX: 1ffff110271dd983 RCX: ffff88810dc23b40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000030 RBP: ffffc90000c27b30 R08: 0000000000000000 R09: 0000000050000028 R10: dffffc0000000000 R11: fffffbfff0dcf648 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fcdeb06f6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010cd5e000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_force_split_extent_at fs/ext4/extents.c:318 [inline] ext4_ext_remove_space+0x631/0x4570 fs/ext4/extents.c:2875 ext4_collapse_range fs/ext4/extents.c:5429 [inline] ext4_fallocate+0x1006/0x1a70 fs/ext4/extents.c:4769 vfs_fallocate+0x4b4/0x590 fs/open.c:310 ksys_fallocate fs/open.c:333 [inline] __do_sys_fallocate fs/open.c:341 [inline] __se_sys_fallocate fs/open.c:339 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:339 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fcdec635819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcdeb06f028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fcdec8af090 RCX: 00007fcdec635819 RDX: 0000000000004000 RSI: 0000000000000008 RDI: 0000000000000005 RBP: 00007fcdec6cbc91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcdec8af128 R14: 00007fcdec8af090 R15: 00007fff2a4e7b58 Modules linked in: ---[ end trace e26c445e97c67ecb ]--- RIP: 0010:ext4_split_extent_at+0xe1f/0xe40 fs/ext4/extents.c:3184 Code: a7 cf d2 ff e9 05 fc ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c 12 fc ff ff 48 89 df e8 6b cf d2 ff e9 05 fc ff ff e8 81 4f 98 ff <0f> 0b e8 7a 4f 98 ff 0f 0b e8 73 4f 98 ff 0f 0b e8 6c 4f 98 ff 0f RSP: 0018:ffffc90000c279e0 EFLAGS: 00010293 RAX: ffffffff81cc63cf RBX: 1ffff110271dd983 RCX: ffff88810dc23b40 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000030 RBP: ffffc90000c27b30 R08: 0000000000000000 R09: 0000000050000028 R10: dffffc0000000000 R11: fffffbfff0dcf648 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fcdeb06f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcdec682f00 CR3: 000000010cd5e000 CR4: 00000000003526a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400