diff options
Diffstat (limited to 'lib/ts_kmp.c')
| -rw-r--r-- | lib/ts_kmp.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/lib/ts_kmp.c b/lib/ts_kmp.c index 5520dc28255a..29466c1803c9 100644 --- a/lib/ts_kmp.c +++ b/lib/ts_kmp.c @@ -94,8 +94,22 @@ static struct ts_config *kmp_init(const void *pattern, unsigned int len, struct ts_config *conf; struct ts_kmp *kmp; int i; - unsigned int prefix_tbl_len = len * sizeof(unsigned int); - size_t priv_size = sizeof(*kmp) + len + prefix_tbl_len; + unsigned int prefix_tbl_len; + size_t priv_size; + + /* Zero-length patterns would make kmp_find() read beyond kmp->pattern. */ + if (unlikely(!len)) + return ERR_PTR(-EINVAL); + + /* + * kmp->pattern is stored immediately after the prefix_tbl[] table. + * Reject lengths that would wrap while sizing either region. + */ + if (unlikely(check_mul_overflow(len, sizeof(*kmp->prefix_tbl), + &prefix_tbl_len) || + check_add_overflow(sizeof(*kmp), (size_t)len, &priv_size) || + check_add_overflow(priv_size, prefix_tbl_len, &priv_size))) + return ERR_PTR(-EINVAL); conf = alloc_ts_config(priv_size, gfp_mask); if (IS_ERR(conf)) |