================================================================== BUG: KASAN: slab-use-after-free in iov_iter_folioq_advance+0x10c/0x360 lib/iov_iter.c:540 Read of size 8 at addr ffff88801fd92520 by task syz-executor251/5100 CPU: 0 UID: 0 PID: 5100 Comm: syz-executor251 Not tainted 6.11.0-syzkaller-02520-gadfc3ded5c33 #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+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 iov_iter_folioq_advance+0x10c/0x360 lib/iov_iter.c:540 netfs_write_folio+0x154b/0x1fe0 fs/netfs/write_issue.c:481 netfs_writepages+0x89f/0xe80 fs/netfs/write_issue.c:541 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [inline] __filemap_fdatawrite mm/filemap.c:436 [inline] filemap_fdatawrite+0xfb/0x160 mm/filemap.c:441 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f354c1210c9 Code: Unable to access opcode bytes at 0x7f354c12109f. RSP: 002b:00007ffdcf751d08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f354c1210c9 RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000 RBP: 00007f354c19c390 R08: ffffffffffffffb8 R09: 0000000000000006 R10: 000000007ffff000 R11: 0000000000000246 R12: 00007f354c19c390 R13: 0000000000000000 R14: 00007f354c19cde0 R15: 00007f354c0f20b0 Allocated by task 5100: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4190 kmalloc_noprof include/linux/slab.h:690 [inline] netfs_buffer_append_folio+0x1f1/0x8b0 fs/netfs/misc.c:25 netfs_write_folio+0xe69/0x1fe0 fs/netfs/write_issue.c:421 netfs_writepages+0x89f/0xe80 fs/netfs/write_issue.c:541 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [inline] __filemap_fdatawrite mm/filemap.c:436 [inline] filemap_fdatawrite+0xfb/0x160 mm/filemap.c:441 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x27f0 kernel/exit.c:882 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 1030: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 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+0x149/0x360 mm/slub.c:4595 netfs_delete_buffer_head+0x9f/0xd0 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+0x1b9a/0x4950 fs/netfs/write_collect.c:551 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x870/0xd30 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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 ffff88801fd92400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff88801fd92400, ffff88801fd92600) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1fd92 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff88801ac41c80 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080080008 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff88801ac41c80 dead000000000122 0000000000000000 head: 0000000000000000 0000000080080008 00000001fdffffff 0000000000000000 head: 00fff00000000001 ffffea00007f6481 ffffffffffffffff 0000000000000000 head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5100, tgid 5100 (syz-executor251), ts 89108296142, free_ts 87555671864 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500 prep_new_page mm/page_alloc.c:1508 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3446 __alloc_pages_noprof+0x256/0x6c0 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+0x5f/0x120 mm/slub.c:2319 allocate_slab+0x5a/0x2f0 mm/slub.c:2482 new_slab mm/slub.c:2535 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3721 __slab_alloc+0x58/0xa0 mm/slub.c:3811 __slab_alloc_node mm/slub.c:3864 [inline] slab_alloc_node mm/slub.c:4026 [inline] __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4185 kmalloc_noprof include/linux/slab.h:690 [inline] netfs_buffer_append_folio+0x1f1/0x8b0 fs/netfs/misc.c:25 netfs_write_folio+0xe69/0x1fe0 fs/netfs/write_issue.c:421 netfs_writepages+0x89f/0xe80 fs/netfs/write_issue.c:541 do_writepages+0x35d/0x870 mm/page-writeback.c:2683 filemap_fdatawrite_wbc+0x125/0x180 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:430 [inline] __filemap_fdatawrite mm/filemap.c:436 [inline] filemap_fdatawrite+0xfb/0x160 mm/filemap.c:441 v9fs_dir_release+0x151/0x560 fs/9p/vfs_dir.c:219 __fput+0x23f/0x880 fs/file_table.c:431 page last free pid 5094 tgid 5094 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1101 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2619 skb_free_frag include/linux/skbuff.h:3399 [inline] skb_free_head net/core/skbuff.c:1096 [inline] skb_release_data+0x6dc/0x8a0 net/core/skbuff.c:1125 skb_release_all net/core/skbuff.c:1190 [inline] __napi_kfree_skb net/core/skbuff.c:1480 [inline] kfree_skb_napi_cache net/core/skbuff.c:7115 [inline] skb_attempt_defer_free+0x42f/0x5c0 net/core/skbuff.c:7137 tcp_eat_recv_skb net/ipv4/tcp.c:1526 [inline] tcp_recvmsg_locked+0x2995/0x3c80 net/ipv4/tcp.c:2805 tcp_recvmsg+0x25d/0x920 net/ipv4/tcp.c:2851 inet_recvmsg+0x150/0x2d0 net/ipv4/af_inet.c:885 sock_recvmsg_nosec net/socket.c:1052 [inline] sock_recvmsg+0x1ae/0x280 net/socket.c:1074 sock_read_iter+0x2c4/0x3d0 net/socket.c:1144 new_sync_read fs/read_write.c:488 [inline] vfs_read+0x9bb/0xbc0 fs/read_write.c:569 ksys_read+0x1a0/0x2c0 fs/read_write.c:712 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88801fd92400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801fd92480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801fd92500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801fd92580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801fd92600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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