Hello, syzbot found the following issue on: HEAD commit: 614cb2751d31 Merge tag 'trace-v5.14-rc6' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=164bc961300000 kernel config: https://syzkaller.appspot.com/x/.config?x=f61012d0b1cd846f dashboard link: https://syzkaller.appspot.com/bug?extid=333dc3792ca8ce20b80c compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+333dc3792ca8ce20b80c@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:784 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xae9/0xcc0 fs/ext4/extents.c:904 Read of size 4 at addr ffff888043db6024 by task kworker/u4:11/12775 CPU: 0 PID: 12775 Comm: kworker/u4:11 Not tainted 5.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:5) Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105 print_address_description+0x66/0x3b0 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report+0x163/0x210 mm/kasan/report.c:436 ext4_ext_binsearch fs/ext4/extents.c:784 [inline] ext4_find_extent+0xae9/0xcc0 fs/ext4/extents.c:904 ext4_ext_map_blocks+0x1e7/0x7210 fs/ext4/extents.c:4061 ext4_map_blocks+0xab3/0x1cb0 fs/ext4/inode.c:638 mpage_map_one_extent fs/ext4/inode.c:2395 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2448 [inline] ext4_writepages+0x1797/0x3f30 fs/ext4/inode.c:2800 do_writepages+0x12e/0x2b0 mm/page-writeback.c:2355 __writeback_single_inode+0xd4/0x590 fs/fs-writeback.c:1613 writeback_sb_inodes+0xd8e/0x2b80 fs/fs-writeback.c:1878 wb_writeback+0x423/0x9c0 fs/fs-writeback.c:2051 wb_do_writeback fs/fs-writeback.c:2196 [inline] wb_workfn+0x41b/0x13c0 fs/fs-writeback.c:2237 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the page: page:ffffea00010f6d80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x100 pfn:0x43db6 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001189248 ffffea00015da888 0000000000000000 raw: 0000000000000100 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x1101cca(GFP_HIGHUSER_MOVABLE|__GFP_WRITE), pid 20166, ts 379239124786, free_ts 380213300070 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4169 __alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5391 __page_cache_alloc+0x79/0x1c0 mm/filemap.c:1005 pagecache_get_page+0x85e/0xf70 mm/filemap.c:1885 grab_cache_page_write_begin+0x50/0x90 mm/filemap.c:3610 ext4_da_write_begin+0x539/0x10c0 fs/ext4/inode.c:2984 generic_perform_write+0x262/0x580 mm/filemap.c:3656 ext4_buffered_write_iter+0x41c/0x590 fs/ext4/file.c:269 ext4_file_write_iter+0x8f7/0x1b90 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2114 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0xa39/0xc90 fs/read_write.c:605 ksys_write+0x171/0x2a0 fs/read_write.c:658 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0xc29/0xd20 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page_list+0x118/0xad0 mm/page_alloc.c:3448 release_pages+0x18bb/0x1af0 mm/swap.c:972 __pagevec_release+0x7d/0xf0 mm/swap.c:992 pagevec_release include/linux/pagevec.h:81 [inline] truncate_inode_pages_range+0x472/0x12d0 mm/truncate.c:329 ext4_evict_inode+0x424/0xf70 fs/ext4/inode.c:223 evict+0x2a4/0x620 fs/inode.c:584 do_unlinkat+0x528/0x990 fs/namei.c:4109 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff888043db5f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888043db5f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888043db6000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888043db6080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888043db6100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== --- This report is generated by a bot. 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