forked from luck/tmp_suning_uos_patched
79a8a642bf
Most callers of put_cmsg() use a "sizeof(foo)" for the length argument.
Within put_cmsg(), a copy_to_user() call is made with a dynamic size, as a
result of the cmsg header calculations. This means that hardened usercopy
will examine the copy, even though it was technically a fixed size and
should be implicitly whitelisted. All the put_cmsg() calls being built
from values in skbuff_head_cache are coming out of the protocol-defined
"cb" field, so whitelist this field entirely instead of creating per-use
bounce buffers, for which there are concerns about performance.
Original report was:
Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLAB object 'skbuff_head_cache' (offset 64, size 16)!
WARNING: CPU: 0 PID: 3663 at mm/usercopy.c:81 usercopy_warn+0xdb/0x100 mm/usercopy.c:76
...
__check_heap_object+0x89/0xc0 mm/slab.c:4426
check_heap_object mm/usercopy.c:236 [inline]
__check_object_size+0x272/0x530 mm/usercopy.c:259
check_object_size include/linux/thread_info.h:112 [inline]
check_copy_size include/linux/thread_info.h:143 [inline]
copy_to_user include/linux/uaccess.h:154 [inline]
put_cmsg+0x233/0x3f0 net/core/scm.c:242
sock_recv_errqueue+0x200/0x3e0 net/core/sock.c:2913
packet_recvmsg+0xb2e/0x17a0 net/packet/af_packet.c:3296
sock_recvmsg_nosec net/socket.c:803 [inline]
sock_recvmsg+0xc9/0x110 net/socket.c:810
___sys_recvmsg+0x2a4/0x640 net/socket.c:2179
__sys_recvmmsg+0x2a9/0xaf0 net/socket.c:2287
SYSC_recvmmsg net/socket.c:2368 [inline]
SyS_recvmmsg+0xc4/0x160 net/socket.c:2352
entry_SYSCALL_64_fastpath+0x29/0xa0
Reported-by: syzbot+e2d6cfb305e9f3911dea@syzkaller.appspotmail.com
Fixes:
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|---|---|---|
| .. | ||
| 6lowpan | ||
| 9p | ||
| 802 | ||
| 8021q | ||
| appletalk | ||
| atm | ||
| ax25 | ||
| batman-adv | ||
| bluetooth | ||
| bpf | ||
| bridge | ||
| caif | ||
| can | ||
| ceph | ||
| core | ||
| dcb | ||
| dccp | ||
| decnet | ||
| dns_resolver | ||
| dsa | ||
| ethernet | ||
| hsr | ||
| ieee802154 | ||
| ife | ||
| ipv4 | ||
| ipv6 | ||
| iucv | ||
| kcm | ||
| key | ||
| l2tp | ||
| l3mdev | ||
| lapb | ||
| llc | ||
| mac80211 | ||
| mac802154 | ||
| mpls | ||
| ncsi | ||
| netfilter | ||
| netlabel | ||
| netlink | ||
| netrom | ||
| nfc | ||
| nsh | ||
| openvswitch | ||
| packet | ||
| phonet | ||
| psample | ||
| qrtr | ||
| rds | ||
| rfkill | ||
| rose | ||
| rxrpc | ||
| sched | ||
| sctp | ||
| smc | ||
| strparser | ||
| sunrpc | ||
| switchdev | ||
| tipc | ||
| tls | ||
| unix | ||
| vmw_vsock | ||
| wimax | ||
| wireless | ||
| x25 | ||
| xfrm | ||
| compat.c | ||
| Kconfig | ||
| Makefile | ||
| socket.c | ||
| sysctl_net.c | ||