================================================================== BUG: KASAN: slab-out-of-bounds in should_fault_in_pages fs/gfs2/file.c:785 [inline] BUG: KASAN: slab-out-of-bounds in gfs2_file_buffered_write+0x576/0x900 fs/gfs2/file.c:1070 Read of size 8 at addr ffff88802557cf00 by task syz.0.66/4562 CPU: 1 PID: 4562 Comm: syz.0.66 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 should_fault_in_pages fs/gfs2/file.c:785 [inline] gfs2_file_buffered_write+0x576/0x900 fs/gfs2/file.c:1070 gfs2_file_write_iter+0xfaf/0x1240 fs/gfs2/file.c:1145 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1 do_iter_write+0x205/0x7b0 fs/read_write.c:855 iter_file_splice_write+0x699/0xcc0 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0xe1/0x130 fs/splice.c:956 splice_direct_to_actor+0x4ea/0xc10 fs/splice.c:902 do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008 generic_copy_file_range fs/read_write.c:1385 [inline] vfs_copy_file_range+0xb31/0x1480 fs/read_write.c:1531 __do_sys_copy_file_range fs/read_write.c:1588 [inline] __se_sys_copy_file_range+0x320/0x470 fs/read_write.c:1551 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 RIP: 0033:0x7fa353648cb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa3518a4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000146 RAX: ffffffffffffffda RBX: 00007fa3538c3fa0 RCX: 00007fa353648cb9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fa3536b6bf7 R08: fffffbffa003e458 R09: 0100000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa3538c4038 R14: 00007fa3538c3fa0 R15: 00007ffd3ef1d108 Allocated by task 4562: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc_array include/linux/slab.h:647 [inline] kcalloc include/linux/slab.h:676 [inline] iter_file_splice_write+0x19f/0xcc0 fs/splice.c:628 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0xe1/0x130 fs/splice.c:956 splice_direct_to_actor+0x4ea/0xc10 fs/splice.c:902 do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008 generic_copy_file_range fs/read_write.c:1385 [inline] vfs_copy_file_range+0xb31/0x1480 fs/read_write.c:1531 __do_sys_copy_file_range fs/read_write.c:1588 [inline] __se_sys_copy_file_range+0x320/0x470 fs/read_write.c:1551 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 The buggy address belongs to the object at ffff88802557ce00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes to the right of 256-byte region [ffff88802557ce00, ffff88802557cf00) The buggy address belongs to the page: page:ffffea0000955f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2557c head:ffffea0000955f00 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001e05000 0000000500000005 ffff888016c41b40 raw: 0000000000000000 0000000080100010 00000001ffffffff 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4338, ts 80867036932, free_ts 80302232919 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:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] set_kthread_struct kernel/kthread.c:103 [inline] kthread+0x10b/0x520 kernel/kthread.c:296 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3238 vm_area_dup+0x1e/0xb0 kernel/fork.c:358 __split_vma+0xb1/0x410 mm/mmap.c:2730 __do_munmap+0x383/0xdf0 mm/mmap.c:2856 __vm_munmap+0x140/0x240 mm/mmap.c:2952 __do_sys_munmap mm/mmap.c:2978 [inline] __se_sys_munmap mm/mmap.c:2974 [inline] __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974 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 Memory state around the buggy address: ffff88802557ce00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802557ce80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88802557cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802557cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802557d000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================