[libvirt] [PATCH] Fix Invalid write in virCryptoHashString()

While running vircryptotest, it was found that valgrind pointed out the following error: ==27453== Invalid write of size 1 ==27453== at 0x4C7D7C9: virCryptoHashString (vircrypto.c:76) ==27453== by 0x401C4E: testCryptoHash (vircryptotest.c:41) ==27453== by 0x402A11: virtTestRun (testutils.c:199) ==27453== by 0x401AD5: mymain (vircryptotest.c:76) ==27453== by 0x40318D: virtTestMain (testutils.c:782) ==27453== by 0x3E6CE1ED1C: (below main) (libc-start.c:226) ==27453== Address 0x51f0541 is 0 bytes after a block of size 65 alloc'd ==27453== at 0x4A0577B: calloc (vg_replace_malloc.c:593) ==27453== by 0x4C69F2E: virAllocN (viralloc.c:189) ==27453== by 0x4C7D76B: virCryptoHashString (vircrypto.c:69) ==27453== by 0x401C4E: testCryptoHash (vircryptotest.c:41) ==27453== by 0x402A11: virtTestRun (testutils.c:199) ==27453== by 0x401AD5: mymain (vircryptotest.c:76) ==27453== by 0x40318D: virtTestMain (testutils.c:782) ==27453== by 0x3E6CE1ED1C: (below main) (libc-start.c:226) ==27453== ...and many more --- The errors go away, if I either do: Line 76: (*output)[hashstrlen - 1] = '\0'; or Line 61: if (VIR_ALLOC_N(*output, hashstrlen + 1) < 0) But the second one seems less harmful, as anyway we are going to free that memory. src/util/vircrypto.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/util/vircrypto.c b/src/util/vircrypto.c index 3af3aa3..aa2b0c8 100644 --- a/src/util/vircrypto.c +++ b/src/util/vircrypto.c @@ -66,7 +66,7 @@ virCryptoHashString(virCryptoHash hash, return -1; } - if (VIR_ALLOC_N(*output, hashstrlen) < 0) + if (VIR_ALLOC_N(*output, hashstrlen + 1) < 0) return -1; for (i = 0; i < hashinfo[hash].hashlen; i++) { -- 1.7.1