================================================================== BUG: KASAN: slab-use-after-free in metapage_write_folio+0xc95/0xcf0 fs/jfs/jfs_metapage.c:462 Read of size 4 at addr ffff888038cc5210 by task syz.2.265/7439 CPU: 1 UID: 0 PID: 7439 Comm: syz.2.265 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 metapage_write_folio+0xc95/0xcf0 fs/jfs/jfs_metapage.c:462 metapage_writepages+0xe8/0x1a0 fs/jfs/jfs_metapage.c:559 do_writepages+0x32e/0x550 mm/page-writeback.c:2571 filemap_writeback mm/filemap.c:388 [inline] filemap_fdatawrite_range mm/filemap.c:413 [inline] filemap_write_and_wait_range+0x338/0x3f0 mm/filemap.c:685 filemap_write_and_wait include/linux/pagemap.h:65 [inline] jfs_umount+0x2cc/0x3d0 fs/jfs/jfs_umount.c:103 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x22c0 kernel/exit.c:975 do_group_exit+0x21b/0x2d0 kernel/exit.c:1117 get_signal+0x125c/0x1310 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa76d5dcdd9 Code: Unable to access opcode bytes at 0x7fa76d5dcdaf. RSP: 002b:00007fa76b82e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: 0000000000000000 RBX: 00007fa76d855fa0 RCX: 00007fa76d5dcdd9 RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000000 RBP: 00007fa76d672d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000001000021 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa76d856038 R14: 00007fa76d855fa0 R15: 00007ffcee2ddd28 Allocated by task 7439: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5419 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1157 [inline] lmLogOpen+0x2d1/0xfa0 fs/jfs/jfs_logmgr.c:1067 jfs_mount_rw+0xee/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7439: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6250 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6565 lmLogClose+0x297/0x520 fs/jfs/jfs_logmgr.c:-1 jfs_reconfigure+0x6f6/0xa00 fs/jfs/super.c:421 reconfigure_super+0x227/0x8a0 fs/super.c:1080 do_remount fs/namespace.c:3400 [inline] path_mount+0xdc5/0x10e0 fs/namespace.c:4146 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888038cc5000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 528 bytes inside of freed 1024-byte region [ffff888038cc5000, ffff888038cc5400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x38cc0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88801a00bdc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88801a00bdc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 16, tgid 16 (ktimers/0), ts 229618107197, free_ts 229555523359 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7255 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] ieee802_11_parse_elems_full+0x159/0x2ab0 net/mac80211/parse.c:1051 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2518 [inline] ieee80211_inform_bss+0x161/0x1160 net/mac80211/scan.c:79 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd2f/0x1b80 net/wireless/scan.c:2372 cfg80211_inform_bss_data+0x266/0x3c40 net/wireless/scan.c:3226 cfg80211_inform_bss_frame_data+0x3c7/0x730 net/wireless/scan.c:3317 ieee80211_bss_info_update+0x794/0xa40 net/mac80211/scan.c:230 ieee80211_scan_rx+0x552/0xa40 net/mac80211/scan.c:364 __ieee80211_rx_handle_packet net/mac80211/rx.c:5353 [inline] ieee80211_rx_list+0x2a02/0x3760 net/mac80211/rx.c:5636 ieee80211_rx_napi+0x1b1/0x3e0 net/mac80211/rx.c:5659 page last free pid 4964 tgid 4964 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943 __slab_free+0x252/0x2a0 mm/slub.c:5612 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905 alloc_filename fs/namei.c:142 [inline] do_getname+0x2e/0x250 fs/namei.c:182 class_filename_flags_constructor include/linux/fs.h:2555 [inline] do_readlinkat+0xc8/0x510 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888038cc5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888038cc5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888038cc5200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888038cc5280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888038cc5300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================