From bfc6fe2bac8ac262075271c2f6649b28cd04f883 Mon Sep 17 00:00:00 2001 From: Zdenek Kabelac Date: Mon, 20 Sep 2021 01:46:43 +0200 Subject: [PATCH] cov: ensure data is not derefenced Ensure all hypothetical paths cannot dereference NULL *(u->data). --- lib/device/bcache-utils.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/lib/device/bcache-utils.c b/lib/device/bcache-utils.c index 85ec07aa6..82adb89a9 100644 --- a/lib/device/bcache-utils.c +++ b/lib/device/bcache-utils.c @@ -164,8 +164,10 @@ static bool _write_partial(struct updater *u, int di, block_address bb, if (!bcache_get(u->cache, di, bb, GF_DIRTY, &b)) return false; - memcpy(((unsigned char *) b->data) + offset, u->data, len); - u->data = ((unsigned char *) u->data) + len; + if (u->data) { + memcpy(((unsigned char *) b->data) + offset, u->data, len); + u->data = ((unsigned char *) u->data) + len; + } bcache_put(b); return true; @@ -246,7 +248,7 @@ bool bcache_zero_bytes(struct bcache *cache, int di, uint64_t start, size_t len) static bool _set_partial(struct updater *u, int di, block_address bb, uint64_t offset, size_t len) { struct block *b; - uint8_t val = *((uint8_t *) u->data); + uint8_t val = (u->data) ? *((uint8_t *) u->data) : 0; if (!bcache_get(u->cache, di, bb, GF_DIRTY, &b)) return false; @@ -260,7 +262,7 @@ static bool _set_partial(struct updater *u, int di, block_address bb, uint64_t o static bool _set_whole(struct updater *u, int di, block_address bb, block_address be) { struct block *b; - uint8_t val = *((uint8_t *) u->data); + uint8_t val = (u->data) ? *((uint8_t *) u->data) : 0; uint64_t len = bcache_block_sectors(u->cache) * 512; for (; bb != be; bb++) {