================================================================== BUG: KASAN: slab-use-after-free in bchfs_read+0x1678/0x1f6c fs/bcachefs/fs-io-buffered.c:228 Read of size 4 at addr ffff0000cddb2648 by task syz.0.305/7768 CPU: 0 UID: 0 PID: 7768 Comm: syz.0.305 Not tainted 6.15.0-rc1-syzkaller-g0af2f6be1b42 #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x198/0x550 mm/kasan/report.c:521 kasan_report+0xd8/0x138 mm/kasan/report.c:634 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 bchfs_read+0x1678/0x1f6c fs/bcachefs/fs-io-buffered.c:228 bch2_readahead+0xb50/0xf5c fs/bcachefs/fs-io-buffered.c:301 read_pages+0x150/0x4f0 mm/readahead.c:160 page_cache_ra_order+0x7d0/0xb8c mm/readahead.c:515 page_cache_sync_ra+0x568/0x70c mm/readahead.c:621 filemap_get_pages+0x3ec/0x1cdc mm/filemap.c:2590 filemap_read+0x360/0xe94 mm/filemap.c:2701 bch2_read_iter+0x260/0x112c fs/bcachefs/fs-io-direct.c:221 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x698/0x974 fs/read_write.c:570 ksys_read+0x15c/0x26c fs/read_write.c:713 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:720 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 7768: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4151 [inline] slab_alloc_node mm/slub.c:4200 [inline] kmem_cache_alloc_noprof+0x254/0x410 mm/slub.c:4207 mempool_alloc_slab+0x58/0x74 mm/mempool.c:559 mempool_alloc_noprof+0x150/0x48c mm/mempool.c:402 bio_alloc_bioset+0x20c/0x1018 block/bio.c:554 bch2_readahead+0x944/0xf5c fs/bcachefs/fs-io-buffered.c:290 read_pages+0x150/0x4f0 mm/readahead.c:160 page_cache_ra_order+0x7d0/0xb8c mm/readahead.c:515 page_cache_sync_ra+0x568/0x70c mm/readahead.c:621 filemap_get_pages+0x3ec/0x1cdc mm/filemap.c:2590 filemap_read+0x360/0xe94 mm/filemap.c:2701 bch2_read_iter+0x260/0x112c fs/bcachefs/fs-io-direct.c:221 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x698/0x974 fs/read_write.c:570 ksys_read+0x15c/0x26c fs/read_write.c:713 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:720 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Freed by task 10: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_free_info+0x54/0x6c mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x64/0x8c mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free_after_rcu_debug+0x11c/0x2f8 mm/slub.c:4696 rcu_do_batch kernel/rcu/tree.c:2568 [inline] rcu_core+0x898/0x1b5c kernel/rcu/tree.c:2824 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2841 handle_softirqs+0x320/0xd34 kernel/softirq.c:579 __do_softirq+0x14/0x20 kernel/softirq.c:613 Last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:47 kasan_record_aux_stack+0xb4/0xcc mm/kasan/generic.c:548 slab_free_hook mm/slub.c:2350 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x368/0x554 mm/slub.c:4748 mempool_free_slab+0x28/0x38 mm/mempool.c:566 mempool_free+0xbc/0x2e8 mm/mempool.c:548 bio_free+0x200/0x27c block/bio.c:237 bio_put+0x1b8/0x9dc block/bio.c:-1 bch2_readpages_end_io+0x3d4/0x538 fs/bcachefs/fs-io-buffered.c:36 bio_endio+0x840/0x87c block/bio.c:1551 __bch2_read_extent+0x28c0/0x3e68 fs/bcachefs/io_read.c:-1 bch2_read_extent fs/bcachefs/io_read.h:140 [inline] bchfs_read+0x1458/0x1f6c fs/bcachefs/fs-io-buffered.c:226 bch2_readahead+0xb50/0xf5c fs/bcachefs/fs-io-buffered.c:301 read_pages+0x150/0x4f0 mm/readahead.c:160 page_cache_ra_order+0x7d0/0xb8c mm/readahead.c:515 page_cache_sync_ra+0x568/0x70c mm/readahead.c:621 filemap_get_pages+0x3ec/0x1cdc mm/filemap.c:2590 filemap_read+0x360/0xe94 mm/filemap.c:2701 bch2_read_iter+0x260/0x112c fs/bcachefs/fs-io-direct.c:221 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x698/0x974 fs/read_write.c:570 ksys_read+0x15c/0x26c fs/read_write.c:713 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:720 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 The buggy address belongs to the object at ffff0000cddb2500 which belongs to the cache bio-488 of size 488 The buggy address is located 328 bytes inside of freed 488-byte region [ffff0000cddb2500, ffff0000cddb26e8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ddb2 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000d6446280 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800c000c 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000d6446280 dead000000000122 0000000000000000 head: 0000000000000000 00000000800c000c 00000000f5000000 0000000000000000 head: 05ffc00000000001 fffffdffc3376c81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cddb2500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000cddb2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000cddb2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cddb2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff0000cddb2700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================