thunderbolt: xdomain: Avoid potential stack OOB read

tb_xdp_properties_changed_request() was calling tb_xdp_handle_error() with
a struct tb_xdp_properties_changed_response on the stack, which does not
have the "error" field present when cast to struct tb_xdp_error_response.
This was detected when building with -Warray-bounds:

drivers/thunderbolt/xdomain.c: In function 'tb_xdomain_properties_changed':
drivers/thunderbolt/xdomain.c:226:22: error: array subscript 'const struct tb_xdp_error_response[0]' is partly outside array bounds of 'struct tb_xdp_properties_changed_response[1]' [-Werror=array-bounds]
  226 |         switch (error->error) {
      |                 ~~~~~^~~~~~~
drivers/thunderbolt/xdomain.c:448:51: note: while referencing 'res'
  448 |         struct tb_xdp_properties_changed_response res;
      |                                                   ^~~

Add union containing struct tb_xdp_error_response to structures passed
to tb_xdp_handle_error(), so that the "error" field will be present.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Kees Cook 2021-12-06 22:34:13 -08:00 committed by Mika Westerberg
parent 0fcfb00b28
commit 1981355170
2 changed files with 36 additions and 27 deletions

View file

@ -535,15 +535,25 @@ struct tb_xdp_header {
u32 type;
};
struct tb_xdp_error_response {
struct tb_xdp_header hdr;
u32 error;
};
struct tb_xdp_uuid {
struct tb_xdp_header hdr;
};
struct tb_xdp_uuid_response {
struct tb_xdp_header hdr;
uuid_t src_uuid;
u32 src_route_hi;
u32 src_route_lo;
union {
struct tb_xdp_error_response err;
struct {
struct tb_xdp_header hdr;
uuid_t src_uuid;
u32 src_route_hi;
u32 src_route_lo;
};
};
};
struct tb_xdp_properties {
@ -555,13 +565,18 @@ struct tb_xdp_properties {
};
struct tb_xdp_properties_response {
struct tb_xdp_header hdr;
uuid_t src_uuid;
uuid_t dst_uuid;
u16 offset;
u16 data_length;
u32 generation;
u32 data[0];
union {
struct tb_xdp_error_response err;
struct {
struct tb_xdp_header hdr;
uuid_t src_uuid;
uuid_t dst_uuid;
u16 offset;
u16 data_length;
u32 generation;
u32 data[];
};
};
};
/*
@ -580,7 +595,10 @@ struct tb_xdp_properties_changed {
};
struct tb_xdp_properties_changed_response {
struct tb_xdp_header hdr;
union {
struct tb_xdp_error_response err;
struct tb_xdp_header hdr;
};
};
enum tb_xdp_error {
@ -591,9 +609,4 @@ enum tb_xdp_error {
ERROR_NOT_READY,
};
struct tb_xdp_error_response {
struct tb_xdp_header hdr;
u32 error;
};
#endif

View file

@ -214,16 +214,12 @@ static inline void tb_xdp_fill_header(struct tb_xdp_header *hdr, u64 route,
memcpy(&hdr->uuid, &tb_xdp_uuid, sizeof(tb_xdp_uuid));
}
static int tb_xdp_handle_error(const struct tb_xdp_header *hdr)
static int tb_xdp_handle_error(const struct tb_xdp_error_response *res)
{
const struct tb_xdp_error_response *error;
if (hdr->type != ERROR_RESPONSE)
if (res->hdr.type != ERROR_RESPONSE)
return 0;
error = (const struct tb_xdp_error_response *)hdr;
switch (error->error) {
switch (res->error) {
case ERROR_UNKNOWN_PACKET:
case ERROR_UNKNOWN_DOMAIN:
return -EIO;
@ -257,7 +253,7 @@ static int tb_xdp_uuid_request(struct tb_ctl *ctl, u64 route, int retry,
if (ret)
return ret;
ret = tb_xdp_handle_error(&res.hdr);
ret = tb_xdp_handle_error(&res.err);
if (ret)
return ret;
@ -329,7 +325,7 @@ static int tb_xdp_properties_request(struct tb_ctl *ctl, u64 route,
if (ret)
goto err;
ret = tb_xdp_handle_error(&res->hdr);
ret = tb_xdp_handle_error(&res->err);
if (ret)
goto err;
@ -462,7 +458,7 @@ static int tb_xdp_properties_changed_request(struct tb_ctl *ctl, u64 route,
if (ret)
return ret;
return tb_xdp_handle_error(&res.hdr);
return tb_xdp_handle_error(&res.err);
}
static int