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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2016-09-13 09:56:27 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2016-09-13 11:00:55 +0100 |
| commit | 0647d47cc184da587c76743546b6af6dfdb8f1da (patch) | |
| tree | 7c2f3964fb1e4b6408cddd7deeddb2423601a9a9 /block/qcow2.c | |
| parent | 7263da78045dc91cc207f350911efe4259e99b3c (diff) | |
| download | qemu-0647d47cc184da587c76743546b6af6dfdb8f1da.zip qemu-0647d47cc184da587c76743546b6af6dfdb8f1da.tar.gz qemu-0647d47cc184da587c76743546b6af6dfdb8f1da.tar.bz2 | |
qcow2: avoid memcpy(dst, NULL, len)
Section "7.1.4 Use of library functions" in the C99 standard says:
If an argument to a function has an invalid value (such as [...]
a null pointer [...]) [...] the behavior is undefined.
Additionally the "searching and sorting" functions are specified as
requiring valid pointer values as described in 7.1.4.
This patch fixes the following sanitizer errors:
block/qcow2.c:1807:41: runtime error: null pointer passed as argument 2, which is declared to never be null
block/qcow2-cluster.c:86:26: runtime error: null pointer passed as argument 2, which is declared to never be null
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1473758138-19260-1-git-send-email-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/qcow2.c')
| -rw-r--r-- | block/qcow2.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index c079aa8..0e53a4d 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1804,7 +1804,10 @@ static size_t header_ext_add(char *buf, uint32_t magic, const void *s, .magic = cpu_to_be32(magic), .len = cpu_to_be32(len), }; - memcpy(buf + sizeof(QCowExtension), s, len); + + if (len) { + memcpy(buf + sizeof(QCowExtension), s, len); + } return ext_len; } |