================================================================== 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 ffff888058c61500 by task syz.0.86/4803 CPU: 1 PID: 4803 Comm: syz.0.86 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 do_sendfile+0x5fc/0xeb0 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303 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: 0033:0x7faf53fb9cb9 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:00007faf52215028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007faf54234fa0 RCX: 00007faf53fb9cb9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005 RBP: 00007faf54027bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000080000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faf54235038 R14: 00007faf54234fa0 R15: 00007ffff1f9f1d8 Allocated by task 4803: 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 do_sendfile+0x5fc/0xeb0 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1317 [inline] __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303 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 ffff888058c61400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes to the right of 256-byte region [ffff888058c61400, ffff888058c61500) The buggy address belongs to the page: page:ffffea0001631800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58c60 head:ffffea0001631800 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 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 4819, ts 90285982469, free_ts 82155665941 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] __kmalloc+0x1cd/0x330 mm/slub.c:4408 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] do_splice+0xe5a/0x1640 fs/splice.c:1108 __do_splice fs/splice.c:1173 [inline] __do_sys_splice fs/splice.c:1379 [inline] __se_sys_splice+0x34d/0x440 fs/splice.c:1361 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 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_list+0x119/0x820 mm/page_alloc.c:3433 release_pages+0x186c/0x1be0 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x176/0x300 mm/mmu_gather.c:338 exit_mmap+0x3d0/0x640 mm/mmap.c:3218 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x588/0x6e0 kernel/exit.c:550 do_exit+0x5a9/0x20c0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 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: ffff888058c61400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888058c61480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888058c61500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888058c61580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888058c61600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================