diff options
| author | Kees Cook <keescook@chromium.org> | 2023-02-08 15:25:53 -0800 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2023-02-16 11:20:20 -0400 |
| commit | 876e480da2f74715fc70e37723e77ca16a631e35 (patch) | |
| tree | 42b52f41c31ac958764ccb88f183230989e1167d /drivers/infiniband | |
| parent | 5ff31dfcd6d23f9c1bd5dd1a2c648ba499659357 (diff) | |
RDMA/cma: Distinguish between sockaddr_in and sockaddr_in6 by size
Clang can do some aggressive inlining, which provides it with greater
visibility into the sizes of various objects that are passed into
helpers. Specifically, compare_netdev_and_ip() can see through the type
given to the "sa" argument, which means it can generate code for "struct
sockaddr_in" that would have been passed to ipv6_addr_cmp() (that expects
to operate on the larger "struct sockaddr_in6"), which would result in a
compile-time buffer overflow condition detected by memcmp(). Logically,
this state isn't reachable due to the sa_family assignment two callers
above and the check in compare_netdev_and_ip(). Instead, provide a
compile-time check on sizes so the size-mismatched code will be elided
when inlining. Avoids the following warning from Clang:
../include/linux/fortify-string.h:652:4: error: call to '__read_overflow' declared with 'error' attribute: detected read beyond size of object (1st parameter)
__read_overflow();
^
note: In function 'cma_netevent_callback'
note: which inlined function 'node_from_ndev_ip'
1 error generated.
When the underlying object size is not known (e.g. with GCC and older
Clang), the result of __builtin_object_size() is SIZE_MAX, which will also
compile away, leaving the code as it was originally.
Link: https://lore.kernel.org/r/20230208232549.never.139-kees@kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1687
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/core/cma.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 1d2bff91d78b..308155937713 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -479,13 +479,20 @@ static int compare_netdev_and_ip(int ifindex_a, struct sockaddr *sa, if (sa->sa_family != sb->sa_family) return sa->sa_family - sb->sa_family; - if (sa->sa_family == AF_INET) - return memcmp((char *)&((struct sockaddr_in *)sa)->sin_addr, - (char *)&((struct sockaddr_in *)sb)->sin_addr, + if (sa->sa_family == AF_INET && + __builtin_object_size(sa, 0) >= sizeof(struct sockaddr_in)) { + return memcmp(&((struct sockaddr_in *)sa)->sin_addr, + &((struct sockaddr_in *)sb)->sin_addr, sizeof(((struct sockaddr_in *)sa)->sin_addr)); + } + + if (sa->sa_family == AF_INET6 && + __builtin_object_size(sa, 0) >= sizeof(struct sockaddr_in6)) { + return ipv6_addr_cmp(&((struct sockaddr_in6 *)sa)->sin6_addr, + &((struct sockaddr_in6 *)sb)->sin6_addr); + } - return ipv6_addr_cmp(&((struct sockaddr_in6 *)sa)->sin6_addr, - &((struct sockaddr_in6 *)sb)->sin6_addr); + return -1; } static int cma_add_id_to_tree(struct rdma_id_private *node_id_priv) |