nvram: fix "Segmentation fault" caused by setting memory out of buffer

Some MTD partitions with NVRAM have content starting in the middle. In
such case offset is set and nvram_header returns pointer to the middle.
It means we have to respect offset when calculating remaining space.

By the way use real MTD partition size (nvram_part_size variable) as we
may want to bump NVRAM_SPACE in the (very near) future.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Backport of r46251

SVN-Revision: 46258

diff --git a/package/utils/nvram/src/nvram.c b/package/utils/nvram/src/nvram.c
index c4bcb1d4a6f00a97f3fc7bfa2a0795f9cf4a7bb1..c490597d4b8238941acac0fec0b04ed784a15719 100644 (file)
--- a/package/utils/nvram/src/nvram.c
+++ b/package/utils/nvram/src/nvram.c
@@ -286,11 +286,11 @@ int nvram_commit(nvram_handle_t *h)
 
        /* Clear data area */
        ptr = (char *) header + sizeof(nvram_header_t);
-       memset(ptr, 0xFF, NVRAM_SPACE - sizeof(nvram_header_t));
+       memset(ptr, 0xFF, nvram_part_size - h->offset - sizeof(nvram_header_t));
        memset(&tmp, 0, sizeof(nvram_header_t));
 
        /* Leave space for a double NUL at the end */
-       end = (char *) header + NVRAM_SPACE - 2;
+       end = (char *) header + nvram_part_size - h->offset - 2;
 
        /* Write out all tuples */
        for (i = 0; i < NVRAM_ARRAYSIZE(h->nvram_hash); i++) {