================================================================== BUG: KASAN: slab-use-after-free in iov_iter_folioq_advance lib/iov_iter.c:540 [inline] BUG: KASAN: slab-use-after-free in iov_iter_advance+0x677/0x6c0 lib/iov_iter.c:576 Read of size 8 at addr ffff8880309f5520 by task syz.2.1485/10806 CPU: 3 UID: 0 PID: 10806 Comm: syz.2.1485 Not tainted 6.11.0-syzkaller-03917-ga940d9a43e62 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 iov_iter_folioq_advance lib/iov_iter.c:540 [inline] iov_iter_advance+0x677/0x6c0 lib/iov_iter.c:576 netfs_write_folio+0x745/0x18f0 fs/netfs/write_issue.c:481 netfs_writepages+0x2ba/0xb90 fs/netfs/write_issue.c:541 do_writepages+0x1a3/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:397 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:387 __filemap_fdatawrite_range+0xba/0x100 mm/filemap.c:430 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xaa3/0x2bb0 kernel/exit.c:882 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f6805440397 Code: Unable to access opcode bytes at 0x7f680544036d. RSP: 002b:00007f68063621a0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007f680557def9 RDX: 00007f68063621c0 RSI: 00007f68063622f0 RDI: 000000000000000b RBP: 00007f68055f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6805736130 R15: 00007ffeb03ddf48 Allocated by task 10806: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387 kmalloc_noprof include/linux/slab.h:690 [inline] netfs_buffer_append_folio+0x181/0x750 fs/netfs/misc.c:25 netfs_write_folio+0x542/0x18f0 fs/netfs/write_issue.c:421 netfs_writepages+0x2ba/0xb90 fs/netfs/write_issue.c:541 do_writepages+0x1a3/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:397 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:387 __filemap_fdatawrite_range+0xba/0x100 mm/filemap.c:430 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f6/0xb60 fs/file_table.c:431 task_work_run+0x14e/0x250 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xaa3/0x2bb0 kernel/exit.c:882 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031 get_signal+0x25fb/0x2770 kernel/signal.c:2917 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Freed by task 74: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2250 [inline] slab_free mm/slub.c:4474 [inline] kfree+0x12a/0x3b0 mm/slub.c:4595 netfs_delete_buffer_head+0xa6/0x100 fs/netfs/misc.c:59 netfs_writeback_unlock_folios fs/netfs/write_collect.c:139 [inline] netfs_collect_write_results fs/netfs/write_collect.c:493 [inline] netfs_write_collection_worker+0x20f9/0x4f80 fs/netfs/write_collect.c:551 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff8880309f5400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff8880309f5400, ffff8880309f5600) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x309f4 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000002 ffffea0000c27d01 ffffffffffffffff 0000000000000000 head: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4839, tgid 4839 (udevd), ts 19140463048, free_ts 18426068853 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500 prep_new_page mm/page_alloc.c:1508 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3446 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4702 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x4e/0xf0 mm/slub.c:2319 allocate_slab mm/slub.c:2482 [inline] new_slab+0x84/0x260 mm/slub.c:2535 ___slab_alloc+0xdac/0x1870 mm/slub.c:3721 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3811 __slab_alloc_node mm/slub.c:3864 [inline] slab_alloc_node mm/slub.c:4026 [inline] __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4185 kmalloc_noprof include/linux/slab.h:690 [inline] kzalloc_noprof include/linux/slab.h:816 [inline] ep_alloc fs/eventpoll.c:1121 [inline] do_epoll_create+0x62/0x470 fs/eventpoll.c:2185 __do_sys_epoll_create1 fs/eventpoll.c:2216 [inline] __se_sys_epoll_create1 fs/eventpoll.c:2214 [inline] __x64_sys_epoll_create1+0x30/0x40 fs/eventpoll.c:2214 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 4824 tgid 4824 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0x64a/0xe40 mm/page_alloc.c:2619 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3989 [inline] slab_alloc_node mm/slub.c:4038 [inline] __do_kmalloc_node mm/slub.c:4158 [inline] __kmalloc_noprof+0x199/0x400 mm/slub.c:4171 kmalloc_noprof include/linux/slab.h:694 [inline] tomoyo_add_entry security/tomoyo/common.c:2023 [inline] tomoyo_supervisor+0x43d/0xea0 security/tomoyo/common.c:2095 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline] tomoyo_env_perm+0x193/0x210 security/tomoyo/environ.c:63 tomoyo_environ security/tomoyo/domain.c:672 [inline] tomoyo_find_next_domain+0xef9/0x2020 security/tomoyo/domain.c:878 tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline] tomoyo_bprm_check_security+0x12b/0x1d0 security/tomoyo/tomoyo.c:92 security_bprm_check+0x1b9/0x1e0 security/security.c:1296 search_binary_handler fs/exec.c:1808 [inline] exec_binprm fs/exec.c:1862 [inline] bprm_execve fs/exec.c:1913 [inline] bprm_execve+0x642/0x1960 fs/exec.c:1889 do_execveat_common.isra.0+0x4f1/0x630 fs/exec.c:2020 do_execve fs/exec.c:2094 [inline] __do_sys_execve fs/exec.c:2170 [inline] __se_sys_execve fs/exec.c:2165 [inline] __x64_sys_execve+0x8c/0xb0 fs/exec.c:2165 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880309f5400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880309f5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880309f5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880309f5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880309f5600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================