================================================================== BUG: KASAN: slab-use-after-free in iov_iter_folioq_advance+0x10c/0x360 lib/iov_iter.c:540 Read of size 8 at addr ffff888066b37120 by task syz.0.3633/25589 CPU: 0 UID: 0 PID: 25589 Comm: syz.0.3633 Not tainted 6.11.0-syzkaller-04003-gfc1dc0d50780 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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+0x35f/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+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 get_signal+0x15e8/0x1740 kernel/signal.c:2690 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f18e297def9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18e37a5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000593000 RBX: 00007f18e2b35f80 RCX: 00007f18e297def9 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000007 RBP: 00007f18e29f0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f18e2b35f80 R15: 00007ffeb4de4bc8 Allocated by task 25589: 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+0x35f/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+0x241/0x880 fs/file_table.c:431 task_work_run+0x251/0x310 kernel/task_work.c:228 get_signal+0x15e8/0x1740 kernel/signal.c:2690 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 11392: 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+0xa2e/0x1830 kernel/workqueue.c:3312 worker_thread+0x870/0xd30 kernel/workqueue.c:3393 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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 ffff888066b37000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff888066b37000, ffff888066b37200) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x66b34 head: order:2 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 ffffea0000bbec00 dead000000000002 raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff88801ac41c80 ffffea0000bbec00 dead000000000002 head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000 head: 00fff00000000002 ffffea00019acd01 ffffffffffffffff 0000000000000000 head: ffff888000000004 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 18693, tgid 18693 (syz-executor), ts 2208328942227, free_ts 2208264327765 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] __do_kmalloc_node mm/slub.c:4158 [inline] __kmalloc_noprof+0x25a/0x400 mm/slub.c:4171 kmalloc_noprof include/linux/slab.h:694 [inline] kzalloc_noprof include/linux/slab.h:816 [inline] fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3761 addrconf_f6i_alloc+0x3c2/0x7f0 net/ipv6/route.c:4588 ipv6_add_addr+0x5b6/0x1090 net/ipv6/addrconf.c:1120 inet6_addr_add+0x563/0xb00 net/ipv6/addrconf.c:3062 inet6_rtm_newaddr+0x8a3/0xc90 net/ipv6/addrconf.c:5050 rtnetlink_rcv_msg+0x741/0xcf0 net/core/rtnetlink.c:6646 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550 page last free pid 18700 tgid 18700 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 stack_depot_save_flags+0x6f6/0x830 lib/stackdepot.c:666 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_save_track+0x51/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 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] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4045 fill_pool lib/debugobjects.c:168 [inline] debug_objects_fill_pool+0x801/0x9f0 lib/debugobjects.c:615 debug_object_activate+0x135/0x510 lib/debugobjects.c:704 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:3091 [inline] call_rcu+0x97/0xa70 kernel/rcu/tree.c:3210 context_switch kernel/sched/core.c:5191 [inline] __schedule+0x1808/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 nl80211_pre_doit+0x5f/0x8b0 net/wireless/nl80211.c:16580 genl_family_rcv_msg_doit net/netlink/genetlink.c:1110 [inline] genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0xaac/0xec0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 Memory state around the buggy address: ffff888066b37000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888066b37080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888066b37100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888066b37180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888066b37200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================