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linux-user: Perform more checks on iovec lists
Validate count between 0 and IOV_MAX. Limit total length of operation in the same way the kernel does. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Richard Henderson
Riku Voipio
parent
1bdd7c7ea8
commit
f287b2c2d4
@ -1744,55 +1744,96 @@ static abi_long do_getsockopt(int sockfd, int level, int optname,
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return ret;
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}
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/* FIXME
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* lock_iovec()/unlock_iovec() have a return code of 0 for success where
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* other lock functions have a return code of 0 for failure.
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*/
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static abi_long lock_iovec(int type, struct iovec *vec, abi_ulong target_addr,
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int count, int copy)
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static struct iovec *lock_iovec(int type, abi_ulong target_addr,
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int count, int copy)
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{
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struct target_iovec *target_vec;
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abi_ulong base;
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struct iovec *vec;
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abi_ulong total_len, max_len;
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int i;
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target_vec = lock_user(VERIFY_READ, target_addr, count * sizeof(struct target_iovec), 1);
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if (!target_vec)
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return -TARGET_EFAULT;
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for(i = 0;i < count; i++) {
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base = tswapal(target_vec[i].iov_base);
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vec[i].iov_len = tswapal(target_vec[i].iov_len);
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if (vec[i].iov_len != 0) {
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vec[i].iov_base = lock_user(type, base, vec[i].iov_len, copy);
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/* Don't check lock_user return value. We must call writev even
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if a element has invalid base address. */
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} else {
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/* zero length pointer is ignored */
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vec[i].iov_base = NULL;
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}
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if (count == 0) {
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errno = 0;
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return NULL;
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}
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unlock_user (target_vec, target_addr, 0);
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return 0;
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if (count > IOV_MAX) {
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errno = EINVAL;
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return NULL;
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}
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vec = calloc(count, sizeof(struct iovec));
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if (vec == NULL) {
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errno = ENOMEM;
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return NULL;
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}
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target_vec = lock_user(VERIFY_READ, target_addr,
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count * sizeof(struct target_iovec), 1);
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if (target_vec == NULL) {
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errno = EFAULT;
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goto fail2;
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}
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/* ??? If host page size > target page size, this will result in a
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value larger than what we can actually support. */
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max_len = 0x7fffffff & TARGET_PAGE_MASK;
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total_len = 0;
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for (i = 0; i < count; i++) {
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abi_ulong base = tswapal(target_vec[i].iov_base);
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abi_long len = tswapal(target_vec[i].iov_len);
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if (len < 0) {
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errno = EINVAL;
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goto fail;
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} else if (len == 0) {
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/* Zero length pointer is ignored. */
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vec[i].iov_base = 0;
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} else {
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vec[i].iov_base = lock_user(type, base, len, copy);
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if (!vec[i].iov_base) {
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errno = EFAULT;
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goto fail;
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}
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if (len > max_len - total_len) {
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len = max_len - total_len;
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}
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}
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vec[i].iov_len = len;
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total_len += len;
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}
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unlock_user(target_vec, target_addr, 0);
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return vec;
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fail:
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free(vec);
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fail2:
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unlock_user(target_vec, target_addr, 0);
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return NULL;
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}
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static abi_long unlock_iovec(struct iovec *vec, abi_ulong target_addr,
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int count, int copy)
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static void unlock_iovec(struct iovec *vec, abi_ulong target_addr,
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int count, int copy)
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{
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struct target_iovec *target_vec;
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abi_ulong base;
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int i;
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target_vec = lock_user(VERIFY_READ, target_addr, count * sizeof(struct target_iovec), 1);
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if (!target_vec)
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return -TARGET_EFAULT;
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for(i = 0;i < count; i++) {
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if (target_vec[i].iov_base) {
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base = tswapal(target_vec[i].iov_base);
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target_vec = lock_user(VERIFY_READ, target_addr,
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count * sizeof(struct target_iovec), 1);
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if (target_vec) {
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for (i = 0; i < count; i++) {
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abi_ulong base = tswapal(target_vec[i].iov_base);
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abi_long len = tswapal(target_vec[i].iov_base);
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if (len < 0) {
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break;
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}
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unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
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}
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unlock_user(target_vec, target_addr, 0);
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}
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unlock_user (target_vec, target_addr, 0);
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return 0;
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free(vec);
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}
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/* do_socket() Must return target values and target errnos. */
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@ -1888,8 +1929,7 @@ static abi_long do_sendrecvmsg(int fd, abi_ulong target_msg,
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ret = target_to_host_sockaddr(msg.msg_name, tswapal(msgp->msg_name),
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msg.msg_namelen);
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if (ret) {
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unlock_user_struct(msgp, target_msg, send ? 0 : 1);
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return ret;
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goto out2;
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}
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} else {
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msg.msg_name = NULL;
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@ -1900,9 +1940,13 @@ static abi_long do_sendrecvmsg(int fd, abi_ulong target_msg,
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msg.msg_flags = tswap32(msgp->msg_flags);
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count = tswapal(msgp->msg_iovlen);
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vec = alloca(count * sizeof(struct iovec));
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target_vec = tswapal(msgp->msg_iov);
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lock_iovec(send ? VERIFY_READ : VERIFY_WRITE, vec, target_vec, count, send);
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vec = lock_iovec(send ? VERIFY_READ : VERIFY_WRITE,
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target_vec, count, send);
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if (vec == NULL) {
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ret = -host_to_target_errno(errno);
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goto out2;
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}
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msg.msg_iovlen = count;
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msg.msg_iov = vec;
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@ -1932,6 +1976,7 @@ static abi_long do_sendrecvmsg(int fd, abi_ulong target_msg,
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out:
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unlock_iovec(vec, target_vec, count, !send);
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out2:
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unlock_user_struct(msgp, target_msg, send ? 0 : 1);
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return ret;
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}
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@ -7188,26 +7233,24 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
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break;
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case TARGET_NR_readv:
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{
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int count = arg3;
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struct iovec *vec;
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vec = alloca(count * sizeof(struct iovec));
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if (lock_iovec(VERIFY_WRITE, vec, arg2, count, 0) < 0)
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goto efault;
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ret = get_errno(readv(arg1, vec, count));
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unlock_iovec(vec, arg2, count, 1);
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struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);
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if (vec != NULL) {
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ret = get_errno(readv(arg1, vec, arg3));
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unlock_iovec(vec, arg2, arg3, 1);
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} else {
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ret = -host_to_target_errno(errno);
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}
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}
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break;
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case TARGET_NR_writev:
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{
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int count = arg3;
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struct iovec *vec;
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vec = alloca(count * sizeof(struct iovec));
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if (lock_iovec(VERIFY_READ, vec, arg2, count, 1) < 0)
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goto efault;
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ret = get_errno(writev(arg1, vec, count));
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unlock_iovec(vec, arg2, count, 0);
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struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
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if (vec != NULL) {
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ret = get_errno(writev(arg1, vec, arg3));
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unlock_iovec(vec, arg2, arg3, 0);
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} else {
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ret = -host_to_target_errno(errno);
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}
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}
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break;
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case TARGET_NR_getsid:
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@ -8632,14 +8675,13 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
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#ifdef TARGET_NR_vmsplice
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case TARGET_NR_vmsplice:
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{
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int count = arg3;
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struct iovec *vec;
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vec = alloca(count * sizeof(struct iovec));
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if (lock_iovec(VERIFY_READ, vec, arg2, count, 1) < 0)
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goto efault;
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ret = get_errno(vmsplice(arg1, vec, count, arg4));
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unlock_iovec(vec, arg2, count, 0);
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struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
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if (vec != NULL) {
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ret = get_errno(vmsplice(arg1, vec, arg3, arg4));
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unlock_iovec(vec, arg2, arg3, 0);
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} else {
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ret = -host_to_target_errno(errno);
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}
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}
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break;
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#endif
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