================================================================== 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 ffff8880696d9520 by task syz.0.60/5555 CPU: 0 UID: 0 PID: 5555 Comm: syz.0.60 Not tainted 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f085db7df39 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:00007f085d9f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000dd9000 RBX: 00007f085dd35f80 RCX: 00007f085db7df39 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f085dbf0216 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f085dd35f80 R15: 00007ffc471a2d48 Allocated by task 5555: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 35: 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 mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x14f/0x4b0 mm/slub.c:4728 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+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 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 ffff8880696d9400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff8880696d9400, ffff8880696d9600) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x696d8 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: f5(slab) raw: 00fff00000000040 ffff88801b041c80 ffffea0001aab300 dead000000000002 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041c80 ffffea0001aab300 dead000000000002 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0001a5b601 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 4690, tgid 4690 (udevadm), ts 39120336140, free_ts 38871783070 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 __alloc_pages_noprof+0x223/0x25c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2413 [inline] allocate_slab mm/slub.c:2579 [inline] new_slab+0x28b/0x3f0 mm/slub.c:2632 ___slab_alloc+0xd1d/0x16f0 mm/slub.c:3819 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] kernfs_fop_open+0x28b/0xdb0 fs/kernfs/file.c:623 do_dentry_open+0x6cd/0x1530 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 page last free pid 4723 tgid 4723 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 __put_partials+0x14c/0x170 mm/slub.c:3146 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4142 vm_area_dup+0x21/0x2f0 kernel/fork.c:487 __split_vma+0x181/0x1160 mm/vma.c:384 vms_gather_munmap_vmas+0x38f/0x1750 mm/vma.c:1226 mmap_region+0x376/0x2a60 mm/mmap.c:1387 do_mmap+0xc00/0xfc0 mm/mmap.c:496 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:588 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79 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: ffff8880696d9400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880696d9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880696d9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880696d9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880696d9600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ================================================================== 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 ffff88802f8ef120 by task syz.0.60/5555 CPU: 0 UID: 0 PID: 5555 Comm: syz.0.60 Tainted: G B 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f085db7df39 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:00007f085d9f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000dd9000 RBX: 00007f085dd35f80 RCX: 00007f085db7df39 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f085dbf0216 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f085dd35f80 R15: 00007ffc471a2d48 Allocated by task 5555: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 954: 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 mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x14f/0x4b0 mm/slub.c:4728 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+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 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 ffff88802f8ef000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff88802f8ef000, ffff88802f8ef200) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f8ec 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: f5(slab) raw: 00fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0000be3b01 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 4677, tgid 4677 (udevadm), ts 35251346921, free_ts 35210768071 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 __alloc_pages_noprof+0x223/0x25c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2413 [inline] allocate_slab mm/slub.c:2579 [inline] new_slab+0x28b/0x3f0 mm/slub.c:2632 ___slab_alloc+0xd1d/0x16f0 mm/slub.c:3819 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] kernfs_fop_open+0x28b/0xdb0 fs/kernfs/file.c:623 do_dentry_open+0x6cd/0x1530 fs/open.c:958 vfs_open+0x82/0x3f0 fs/open.c:1088 do_open fs/namei.c:3774 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3933 do_filp_open+0x1dc/0x430 fs/namei.c:3960 do_sys_openat2+0x17a/0x1e0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 page last free pid 4676 tgid 4676 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_node_noprof+0x153/0x310 mm/slub.c:4187 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1322 [inline] netlink_alloc_large_skb+0x69/0x130 net/netlink/af_netlink.c:1206 netlink_sendmsg+0x689/0xd70 net/netlink/af_netlink.c:1876 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0xab2/0xc90 net/socket.c:2603 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2657 __sys_sendmsg+0x117/0x1f0 net/socket.c:2686 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: ffff88802f8ef000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802f8ef080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802f8ef100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802f8ef180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802f8ef200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ================================================================== 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 ffff88802fdd2920 by task syz.0.60/5555 CPU: 1 UID: 0 PID: 5555 Comm: syz.0.60 Tainted: G B 6.11.0-syzkaller-11558-g075dbe9f6e3c #0 Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f085db7df39 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:00007f085d9f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000dd9000 RBX: 00007f085dd35f80 RCX: 00007f085db7df39 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f085dbf0216 R08: 0000000000000000 R09: 0000000000000000 R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f085dd35f80 R15: 00007ffc471a2d48 Allocated by task 5555: 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:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [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+0x1a6/0x7f0 mm/page-writeback.c:2683 filemap_fdatawrite_wbc mm/filemap.c:398 [inline] filemap_fdatawrite_wbc+0x148/0x1c0 mm/filemap.c:388 __filemap_fdatawrite_range+0xb3/0xf0 mm/filemap.c:431 v9fs_dir_release+0x429/0x590 fs/9p/vfs_dir.c:219 __fput+0x3f9/0xb60 fs/file_table.c:431 task_work_run+0x151/0x250 kernel/task_work.c:228 get_signal+0x1ca/0x2770 kernel/signal.c:2690 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12: 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 mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x14f/0x4b0 mm/slub.c:4728 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+0x9c8/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 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 ffff88802fdd2800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 288 bytes inside of freed 512-byte region [ffff88802fdd2800, ffff88802fdd2a00) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2fdd0 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: f5(slab) raw: 00fff00000000040 ffff88801b041c80 0000000000000000 0000000000000001 raw: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000040 ffff88801b041c80 0000000000000000 0000000000000001 head: 0000000000000000 0000000080100010 00000001f5000000 0000000000000000 head: 00fff00000000002 ffffea0000bf7401 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 5225, tgid 5225 (syz-executor), ts 84018325249, free_ts 83911755739 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x101e/0x3070 mm/page_alloc.c:3457 __alloc_pages_noprof+0x223/0x25c0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2413 [inline] allocate_slab mm/slub.c:2579 [inline] new_slab+0x28b/0x3f0 mm/slub.c:2632 ___slab_alloc+0xd1d/0x16f0 mm/slub.c:3819 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __kmalloc_cache_noprof+0x2b4/0x300 mm/slub.c:4291 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] mca_alloc net/ipv6/mcast.c:881 [inline] __ipv6_dev_mc_inc+0x2b7/0xc10 net/ipv6/mcast.c:937 ipv6_add_dev+0xa66/0x1400 net/ipv6/addrconf.c:471 addrconf_notify+0x53e/0x19c0 net/ipv6/addrconf.c:3655 notifier_call_chain+0xbc/0x410 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1996 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] register_netdevice+0x17a0/0x1e90 net/core/dev.c:10520 veth_newlink+0x4fb/0x9e0 drivers/net/veth.c:1861 rtnl_newlink_create net/core/rtnetlink.c:3510 [inline] __rtnl_newlink+0x119a/0x1920 net/core/rtnetlink.c:3730 page last free pid 4638 tgid 4638 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0x5f4/0xdc0 mm/page_alloc.c:2638 __put_partials+0x14c/0x170 mm/slub.c:3146 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x121/0x2f0 mm/slub.c:4142 alloc_buffer_head+0x21/0x160 fs/buffer.c:3020 folio_alloc_buffers+0x2bd/0x830 fs/buffer.c:928 grow_dev_folio fs/buffer.c:1068 [inline] grow_buffers fs/buffer.c:1109 [inline] __getblk_slow+0x231/0x5c0 fs/buffer.c:1135 bdev_getblk+0xb1/0xc0 fs/buffer.c:1437 __getblk include/linux/buffer_head.h:380 [inline] jbd2_journal_get_descriptor_buffer+0x177/0x4c0 fs/jbd2/journal.c:974 jbd2_journal_commit_transaction+0x1ccd/0x65b0 fs/jbd2/commit.c:610 kjournald2+0x1f8/0x760 fs/jbd2/journal.c:201 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88802fdd2800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fdd2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802fdd2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802fdd2980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802fdd2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================