Re: [libvirt] [PATCH] qemu: avoid null pointer dereference

This code has had problems historically. As originally written, in commit 6bcf2501 (Jun 08), it could call unlink on a random string, nuking an unrelated file. Then commit 182a80b9 (Sep 09), the code was rewritten to allocate tmp, with both a use-after-free bug and a chance to call unlink(NULL). Commit e206946 (Mar 11) fixed the use-after-free, but not the NULL dereference. Thanks to clang for catching this! * src/qemu/qemu_driver.c (qemudDomainMemoryPeek): Don't call unlink on NULL. --- src/qemu/qemu_driver.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 16d869d..3ee4720 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5355,7 +5355,8 @@ endjob: cleanup: VIR_FORCE_CLOSE(fd); - unlink (tmp); + if (tmp) + unlink (tmp);

VIR_FREE(tmp); if (vm) virDomainObjUnlock(vm);