Zero length message leads to an empty skb ================================================================== BUG: KASAN: slab-out-of-bounds in dtCompare fs/jfs/jfs_dtree.c:3613 [inline] BUG: KASAN: slab-out-of-bounds in dtSearch+0x131c/0x1f34 fs/jfs/jfs_dtree.c:649 Read of size 1 at addr ffff0000e916c058 by task syz-executor.2/4060 CPU: 1 PID: 4060 Comm: syz-executor.2 Not tainted 5.15.157-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x174/0x1e4 mm/kasan/report.c:451 __asan_report_load1_noabort+0x44/0x50 mm/kasan/report_generic.c:306 dtCompare fs/jfs/jfs_dtree.c:3613 [inline] dtSearch+0x131c/0x1f34 fs/jfs/jfs_dtree.c:649 jfs_lookup+0x164/0x39c fs/jfs/namei.c:1459 __lookup_slow+0x250/0x388 fs/namei.c:1663 lookup_slow+0x60/0x84 fs/namei.c:1680 walk_component+0x394/0x4cc fs/namei.c:1976 link_path_walk+0x5a0/0xc38 path_lookupat+0x90/0x3d0 fs/namei.c:2454 do_o_path+0xa8/0x214 fs/namei.c:3713 path_openat+0x216c/0x26cc fs/namei.c:3735 do_filp_open+0x1a8/0x3b4 fs/namei.c:3769 do_sys_openat2+0x128/0x3d8 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x1f0/0x240 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Allocated by task 4060: 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_slab_alloc+0x8c/0xcc mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x74/0x3f4 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x1dc/0x45c mm/slub.c:3233 jfs_alloc_inode+0x24/0x60 fs/jfs/super.c:105 alloc_inode fs/inode.c:236 [inline] iget_locked+0x180/0x720 fs/inode.c:1244 jfs_iget+0x30/0x364 fs/jfs/inode.c:29 jfs_lookup+0x1e8/0x39c fs/jfs/namei.c:1467 __lookup_slow+0x250/0x388 fs/namei.c:1663 lookup_slow+0x60/0x84 fs/namei.c:1680 walk_component+0x394/0x4cc fs/namei.c:1976 lookup_last fs/namei.c:2431 [inline] path_lookupat+0x13c/0x3d0 fs/namei.c:2455 filename_lookup+0x1c4/0x4c8 fs/namei.c:2484 user_path_at_empty+0x5c/0x1a4 fs/namei.c:2883 user_path_at include/linux/namei.h:57 [inline] __do_sys_quotactl fs/quota/quota.c:946 [inline] __se_sys_quotactl fs/quota/quota.c:915 [inline] __arm64_sys_quotactl+0x190/0x7a4 fs/quota/quota.c:915 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 The buggy address belongs to the object at ffff0000e916b780 which belongs to the cache jfs_ip of size 2240 The buggy address is located 24 bytes to the right of 2240-byte region [ffff0000e916b780, ffff0000e916c040) The buggy address belongs to the page: page:000000005b8bcc3a refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129168 head:000000005b8bcc3a order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff0000eb4c2101 flags: 0x5ffe00000010200(slab|head|node=0|zone=2|lastcpupid=0xfff) raw: 05ffe00000010200 0000000000000000 dead000000000122 ffff0000c667e900 raw: 0000000000000000 00000000800d000d 00000001ffffffff ffff0000eb4c2101 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000e916bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000e916bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000e916c000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ^ ffff0000e916c080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff0000e916c100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ERROR: (device loop2): dtSearch: stack overrun! ERROR: (device loop2): remounting filesystem as read-only btstack dump: bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 bn = 0, index = 0 jfs_lookup: dtSearch returned -5