syzbot reported sco_sock_setsockopt() is copying data without checking user input length. BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline] BUG: KASAN: slab-out-of-bounds in sco_sock_setsockopt+0xc0b/0xf90 net/bluetooth/sco.c:893 Read of size 4 at addr ffff88805f7b15a3 by task syz-executor.5/12578 CPU: 1 PID: 12578 Comm: syz-executor.5 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] copy_from_sockptr include/linux/sockptr.h:55 [inline] sco_sock_setsockopt+0xc0b/0xf90 net/bluetooth/sco.c:893 do_sock_setsockopt+0x3b1/0x720 net/socket.c:2311 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f3c2487dde9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3c256b40c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f3c249abf80 RCX: 00007f3c2487dde9 RDX: 0000000000000010 RSI: 0000000000000112 RDI: 0000000000000008 RBP: 00007f3c248ca47a R08: 0000000000000002 R09: 0000000000000000 R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000004d R14: 00007f3c249abf80 R15: 00007fff5dcf4978 </TASK> Allocated by task 12578: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x233/0x4a0 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] __cgroup_bpf_run_filter_setsockopt+0xd2f/0x1040 kernel/bpf/cgroup.c:1869 do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 The buggy address belongs to the object at ffff88805f7b15a0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 1 bytes to the right of allocated 2-byte region [ffff88805f7b15a0, ffff88805f7b15a2) The buggy address belongs to the physical page: page:ffffea00017dec40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5f7b1 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888014c41280 ffffea0000a26d80 dead000000000002 raw: 0000000000000000 0000000080800080 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5091, tgid 5091 (syz-executor.3), ts 75758857522, free_ts 75730585588 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2175 allocate_slab mm/slub.c:2338 [inline] new_slab+0x84/0x2f0 mm/slub.c:2391 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525 __slab_alloc mm/slub.c:3610 [inline] __slab_alloc_node mm/slub.c:3663 [inline] slab_alloc_node mm/slub.c:3835 [inline] __do_kmalloc_node mm/slub.c:3965 [inline] __kmalloc_node_track_caller+0x2d6/0x4e0 mm/slub.c:3986 kstrdup+0x3a/0x80 mm/util.c:62 __kernfs_new_node+0x9d/0x880 fs/kernfs/dir.c:611 kernfs_new_node+0x13a/0x240 fs/kernfs/dir.c:691 kernfs_create_dir_ns+0x43/0x120 fs/kernfs/dir.c:1052 sysfs_create_dir_ns+0x189/0x3a0 fs/sysfs/dir.c:59 create_dir lib/kobject.c:73 [inline] kobject_add_internal+0x435/0x8d0 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x124/0x190 lib/kobject.c:457 netdev_queue_add_kobject net/core/net-sysfs.c:1786 [inline] netdev_queue_update_kobjects+0x1ee/0x5f0 net/core/net-sysfs.c:1838 register_queue_kobjects net/core/net-sysfs.c:1900 [inline] netdev_register_kobject+0x265/0x320 net/core/net-sysfs.c:2140 page last free pid 5103 tgid 5103 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346 free_unref_page_list+0x5a3/0x850 mm/page_alloc.c:2532 release_pages+0x2744/0x2a80 mm/swap.c:1042 tlb_batch_pages_flush mm/mmu_gather.c:98 [inline] tlb_flush_mmu_free mm/mmu_gather.c:293 [inline] tlb_flush_mmu+0x34d/0x4e0 mm/mmu_gather.c:300 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:392 exit_mmap+0x4b6/0xd40 mm/mmap.c:3300 __mmput+0x115/0x3c0 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:569 do_exit+0x99e/0x27e0 kernel/exit.c:865 do_group_exit+0x207/0x2c0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 do_syscall_64+0xfd/0x240 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Memory state around the buggy address: ffff88805f7b1480: 05 fc fc fc 05 fc fc fc fa fc fc fc 05 fc fc fc ffff88805f7b1500: 05 fc fc fc 05 fc fc fc 05 fc fc fc 05 fc fc fc >ffff88805f7b1580: 04 fc fc fc 02 fc fc fc fa fc fc fc 05 fc fc fc ^ ffff88805f7b1600: fa fc fc fc 05 fc fc fc fa fc fc fc 05 fc fc fc ffff88805f7b1680: 05 fc fc fc 05 fc fc fc 00 fc fc fc fa fc fc fc Fixes: 00398e1d5183 ("Bluetooth: Add support for BT_PKT_STATUS CMSG data for SCO connections") Fixes: b96e9c671b05 ("Bluetooth: Add BT_DEFER_SETUP option to sco socket") Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx> Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx> Cc: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> (supporter:BLUETOOTH SUBSYSTEM) Cc: linux-bluetooth@xxxxxxxxxxxxxxx --- net/bluetooth/sco.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 43daf965a01e4ac5c9329150080b00dcd63c7e1c..9d013f01865fd2509f28eac3bceadf682f0a5edb 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -843,6 +843,10 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname, break; } + if (optlen < sizeof(u32)) { + err = -EINVAL; + break; + } if (copy_from_sockptr(&opt, optval, sizeof(u32))) { err = -EFAULT; break; @@ -890,6 +894,10 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname, break; case BT_PKT_STATUS: + if (optlen < sizeof(u32)) { + err = -EINVAL; + break; + } if (copy_from_sockptr(&opt, optval, sizeof(u32))) { err = -EFAULT; break; -- 2.44.0.478.gd926399ef9-goog