================================================================== BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0xaa5/0x1080 lib/iov_iter.c:820 Read of size 4096 at addr ffff88801f945000 by task kworker/u17:0/3823 CPU: 1 PID: 3823 Comm: kworker/u17:0 Not tainted 6.1.0-rc7-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: loop1 loop_workfn Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x461 mm/kasan/report.c:395 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x141/0x190 mm/kasan/generic.c:189 memcpy+0x24/0x60 mm/kasan/shadow.c:65 copy_page_from_iter_atomic+0xaa5/0x1080 lib/iov_iter.c:820 generic_perform_write+0x2ca/0x570 mm/filemap.c:3761 __generic_file_write_iter+0x2ae/0x4d0 mm/filemap.c:3881 generic_file_write_iter+0xe3/0x350 mm/filemap.c:3913 call_write_iter include/linux/fs.h:2199 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735 do_iter_write+0x182/0x700 fs/read_write.c:861 vfs_iter_write+0x74/0xa0 fs/read_write.c:902 lo_write_bvec drivers/block/loop.c:249 [inline] lo_write_simple drivers/block/loop.c:271 [inline] do_req_filebacked drivers/block/loop.c:495 [inline] loop_handle_cmd drivers/block/loop.c:1864 [inline] loop_process_work+0xdad/0x2070 drivers/block/loop.c:1899 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the physical page: page:ffffea00007e5140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f945 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00007ed088 ffffea00008c1988 ffff888012040500 raw: 0000000000000000 ffff88801f945000 0000000100000008 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 5349, tgid 5348 (syz-executor.0), ts 390671743484, free_ts 390600944050 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4291 __alloc_pages_slowpath.constprop.0+0x36b/0x23d0 mm/page_alloc.c:5092 __alloc_pages+0x4aa/0x5b0 mm/page_alloc.c:5571 __alloc_pages_node include/linux/gfp.h:223 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2570 cache_alloc_refill+0x27f/0x380 mm/slab.c:2943 ____cache_alloc mm/slab.c:3019 [inline] ____cache_alloc mm/slab.c:3002 [inline] __do_cache_alloc mm/slab.c:3202 [inline] slab_alloc_node mm/slab.c:3250 [inline] __kmem_cache_alloc_node+0x44a/0x510 mm/slab.c:3549 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:968 kmalloc_array include/linux/slab.h:605 [inline] kcalloc include/linux/slab.h:636 [inline] iter_file_splice_write+0x16c/0xc90 fs/splice.c:625 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:931 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:886 do_splice_direct+0x1ab/0x280 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1509 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x4d0 mm/page_alloc.c:3483 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline] lmLogShutdown+0x341/0x600 fs/jfs/jfs_logmgr.c:1684 lmLogClose+0x55f/0x6f0 fs/jfs/jfs_logmgr.c:1460 jfs_umount+0x2d7/0x3f0 fs/jfs/jfs_umount.c:116 jfs_put_super+0x85/0x1a0 fs/jfs/super.c:194 generic_shutdown_super+0x158/0x410 fs/super.c:492 kill_block_super+0x9b/0xf0 fs/super.c:1428 deactivate_locked_super+0x98/0x160 fs/super.c:332 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88801f944f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801f944f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88801f945000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801f945080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801f945100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================