BUG: Bad page state in process kworker/u4:0  pfn:7d35f
page:ffffea0001f4d7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x13b pfn:0x7d35f
flags: 0xfff00000002007(locked|referenced|uptodate|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002007 dead000000000100 dead000000000122 0000000000000000
raw: 000000000000013b ffff88807a1e18b8 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x100c40(GFP_NOFS|__GFP_HARDWALL), pid 5286, ts 114851496058, free_ts 112112364920
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 pagecache_get_page+0x9b6/0xf10 mm/filemap.c:1940
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grab_cache_page include/linux/pagemap.h:502 [inline]
 __get_metapage+0x282/0x1060 fs/jfs/jfs_metapage.c:614
 xtSplitPage+0x238/0x1c50 fs/jfs/jfs_xtree.c:985
 xtSplitUp+0x2b7/0x1c60 fs/jfs/jfs_xtree.c:782
 xtInsert+0x403/0xc50 fs/jfs/jfs_xtree.c:604
 extAlloc+0xa1f/0xf80 fs/jfs/jfs_extent.c:148
 jfs_get_block+0x355/0xad0 fs/jfs/inode.c:264
 get_more_blocks fs/direct-io.c:673 [inline]
 do_direct_IO fs/direct-io.c:959 [inline]
 do_blockdev_direct_IO fs/direct-io.c:1276 [inline]
 __blockdev_direct_IO+0x13d4/0x3a70 fs/direct-io.c:1368
 blockdev_direct_IO include/linux/fs.h:3345 [inline]
 jfs_direct_IO+0x119/0x220 fs/jfs/inode.c:349
 generic_file_direct_write+0x22c/0x490 mm/filemap.c:3687
 __generic_file_write_iter+0x2b1/0x4e0 mm/filemap.c:3869
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 __vunmap+0x8b9/0xa50 mm/vmalloc.c:2628
 kcov_mmap+0x89/0x120 kernel/kcov.c:498
 call_mmap include/linux/fs.h:2178 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1796 [inline]
 mmap_region+0xf88/0x1650 mm/mmap.c:2933
 do_mmap+0x819/0xe90 mm/mmap.c:1586
 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551
 ksys_mmap_pgoff+0x54b/0x790 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
Modules linked in:

CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 bad_page+0x14b/0x170 mm/page_alloc.c:652
 check_free_page mm/page_alloc.c:1209 [inline]
 free_pages_prepare mm/page_alloc.c:1334 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x383/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 txUnlock+0x27e/0xcb0 fs/jfs/jfs_txnmgr.c:933
 txCommit+0x4d48/0x5200 fs/jfs/jfs_txnmgr.c:1336
 jfs_commit_inode+0x2ec/0x520 fs/jfs/inode.c:114
 jfs_write_inode+0x141/0x220 fs/jfs/inode.c:138
 write_inode fs/fs-writeback.c:1505 [inline]
 __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715
 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940
 wb_writeback+0x45d/0xbe0 fs/fs-writeback.c:2114
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
page:ffffea0001f4d7c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x13b pfn:0x7d35f
flags: 0xfff00000002007(locked|referenced|uptodate|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002007 dead000000000100 dead000000000122 0000000000000000
raw: 000000000000013b ffff88807a1e18b8 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u))
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x100c40(GFP_NOFS|__GFP_HARDWALL), pid 5286, ts 114851496058, free_ts 112112364920
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 pagecache_get_page+0x9b6/0xf10 mm/filemap.c:1940
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grab_cache_page include/linux/pagemap.h:502 [inline]
 __get_metapage+0x282/0x1060 fs/jfs/jfs_metapage.c:614
 xtSplitPage+0x238/0x1c50 fs/jfs/jfs_xtree.c:985
 xtSplitUp+0x2b7/0x1c60 fs/jfs/jfs_xtree.c:782
 xtInsert+0x403/0xc50 fs/jfs/jfs_xtree.c:604
 extAlloc+0xa1f/0xf80 fs/jfs/jfs_extent.c:148
 jfs_get_block+0x355/0xad0 fs/jfs/inode.c:264
 get_more_blocks fs/direct-io.c:673 [inline]
 do_direct_IO fs/direct-io.c:959 [inline]
 do_blockdev_direct_IO fs/direct-io.c:1276 [inline]
 __blockdev_direct_IO+0x13d4/0x3a70 fs/direct-io.c:1368
 blockdev_direct_IO include/linux/fs.h:3345 [inline]
 jfs_direct_IO+0x119/0x220 fs/jfs/inode.c:349
 generic_file_direct_write+0x22c/0x490 mm/filemap.c:3687
 __generic_file_write_iter+0x2b1/0x4e0 mm/filemap.c:3869
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 __vunmap+0x8b9/0xa50 mm/vmalloc.c:2628
 kcov_mmap+0x89/0x120 kernel/kcov.c:498
 call_mmap include/linux/fs.h:2178 [inline]
 mmap_file+0x5d/0xb0 mm/util.c:1092
 __mmap_region mm/mmap.c:1796 [inline]
 mmap_region+0xf88/0x1650 mm/mmap.c:2933
 do_mmap+0x819/0xe90 mm/mmap.c:1586
 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551
 ksys_mmap_pgoff+0x54b/0x790 mm/mmap.c:1635
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1224!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 9 Comm: kworker/u4:0 Tainted: G    B             syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: writeback wb_workfn (flush-7:3)
RIP: 0010:get_page include/linux/mm.h:1224 [inline]
RIP: 0010:put_metapage+0x278/0x280 fs/jfs/jfs_metapage.c:722
Code: 38 c1 0f 8c 00 ff ff ff 4c 89 ef e8 42 b9 ec fe e9 f3 fe ff ff e8 e8 ad a7 fe 48 8b 3c 24 48 c7 c6 a0 54 62 8a e8 c8 93 da fe <0f> 0b 66 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 70
RSP: 0018:ffffc90000ce7180 EFLAGS: 00010246
RAX: 5b8596e598fcc100 RBX: ffff88807a1e18b8 RCX: 0000000000000000
RDX: 0000000000000044 RSI: 0000000000000000 RDI: fffff5200019ce24
RBP: 000000000000007f R08: ffff8880b9133d7f R09: fffff5200019cde0
R10: dffffc0000000000 R11: ffffed10172267b0 R12: ffff88807a1e18e0
R13: ffffea0001f4d7f4 R14: 1ffff1100f43c31c R15: 1ffff1100f43c329
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb46c1b2f8 CR3: 00000000645c3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 txUnlock+0x427/0xcb0 fs/jfs/jfs_txnmgr.c:948
 txCommit+0x4d48/0x5200 fs/jfs/jfs_txnmgr.c:1336
 jfs_commit_inode+0x2ec/0x520 fs/jfs/inode.c:114
 jfs_write_inode+0x141/0x220 fs/jfs/inode.c:138
 write_inode fs/fs-writeback.c:1505 [inline]
 __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715
 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940
 wb_writeback+0x45d/0xbe0 fs/fs-writeback.c:2114
 wb_do_writeback fs/fs-writeback.c:2257 [inline]
 wb_workfn+0x43a/0xf20 fs/fs-writeback.c:2298
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Modules linked in:
---[ end trace 2b7bcf45081c094a ]---
RIP: 0010:get_page include/linux/mm.h:1224 [inline]
RIP: 0010:put_metapage+0x278/0x280 fs/jfs/jfs_metapage.c:722
Code: 38 c1 0f 8c 00 ff ff ff 4c 89 ef e8 42 b9 ec fe e9 f3 fe ff ff e8 e8 ad a7 fe 48 8b 3c 24 48 c7 c6 a0 54 62 8a e8 c8 93 da fe <0f> 0b 66 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 70
RSP: 0018:ffffc90000ce7180 EFLAGS: 00010246
RAX: 5b8596e598fcc100 RBX: ffff88807a1e18b8 RCX: 0000000000000000
RDX: 0000000000000044 RSI: 0000000000000000 RDI: fffff5200019ce24
RBP: 000000000000007f R08: ffff8880b9133d7f R09: fffff5200019cde0
R10: dffffc0000000000 R11: ffffed10172267b0 R12: ffff88807a1e18e0
R13: ffffea0001f4d7f4 R14: 1ffff1100f43c31c R15: 1ffff1100f43c329
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc6f46d92f8 CR3: 0000000024a2c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400