diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2016-07-07 15:44:43 +0100 |
|---|---|---|
| committer | Riku Voipio <riku.voipio@linaro.org> | 2016-07-19 15:23:17 +0300 |
| commit | a1e221929f570cc84661158421f942b3328a9fd1 (patch) | |
| tree | ff0d7cfba933de9ee8d7dd4dd9a00b793e795105 /linux-user | |
| parent | 31efaef1d9b80b7803e22ef28ffc51df04db60ab (diff) | |
| download | qemu-a1e221929f570cc84661158421f942b3328a9fd1.tar.gz | |
linux-user: Handle short lengths in host_to_target_sockaddr()
If userspace specifies a short buffer for a target sockaddr,
the kernel will only copy in as much as it has space for
(or none at all if the length is zero) -- see the kernel
move_addr_to_user() function. Mimic this in QEMU's
host_to_target_sockaddr() routine.
In particular, this fixes a segfault running the LTP
recvfrom01 test, where the guest makes a recvfrom()
call with a bad buffer pointer and other parameters which
cause the kernel to set the addrlen to zero; because we
did not skip the attempt to swap the sa_family field we
segfaulted on the bad address.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/syscall.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 0a99af8912..ca6a2b495a 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -1376,12 +1376,19 @@ static inline abi_long host_to_target_sockaddr(abi_ulong target_addr, { struct target_sockaddr *target_saddr; + if (len == 0) { + return 0; + } + target_saddr = lock_user(VERIFY_WRITE, target_addr, len, 0); if (!target_saddr) return -TARGET_EFAULT; memcpy(target_saddr, addr, len); - target_saddr->sa_family = tswap16(addr->sa_family); - if (addr->sa_family == AF_NETLINK) { + if (len >= offsetof(struct target_sockaddr, sa_family) + + sizeof(target_saddr->sa_family)) { + target_saddr->sa_family = tswap16(addr->sa_family); + } + if (addr->sa_family == AF_NETLINK && len >= sizeof(struct sockaddr_nl)) { struct sockaddr_nl *target_nl = (struct sockaddr_nl *)target_saddr; target_nl->nl_pid = tswap32(target_nl->nl_pid); target_nl->nl_groups = tswap32(target_nl->nl_groups); |