Re: [libvirt] [PATCH] virsh: Avoid invalid read of size errors

From: Alex Jia&lt;ajia(a)redhat.com&gt; Detected by valgrind. the codes are allocating 0 bytes memory to variable cpumap by vshCalloc function, and then the function VIR_USE_CPU will access it later, a invalid read error will be hit. * tools/virsh.c(cmdVcpuPin): fix invalid read error. * How to reproduce? % valgrind -v --read-var-info=yes virsh vcpupin<domain> 0 0 * Actual result: ==27271== ERROR SUMMARY: 5 errors from 2 contexts (suppressed: 8 from 6) ==27271== ==27271== 1 errors in context 1 of 2: ==27271== Invalid read of size 1 ==27271== at 0x39CF087E2E: __GI_memcpy (in /lib64/libc-2.12.so) ==27271== by 0x39CF114FDC: xdrmem_putbytes (in /lib64/libc-2.12.so) ==27271== by 0x39CF114707: xdr_opaque (in /lib64/libc-2.12.so) ==27271== by 0x4D56194: xdr_remote_domain_pin_vcpu_args (remote_protocol.c:1844) ==27271== by 0x4D6CCE1: virNetMessageEncodePayload (virnetmessage.c:341) ==27271== by 0x4D5A44B: virNetClientProgramCall (virnetclientprogram.c:327) ==27271== by 0x4D36EDB: callWithFD (remote_driver.c:4546) ==27271== by 0x4D36F7B: call (remote_driver.c:4567) ==27271== by 0x4D3B2C1: remoteDomainPinVcpu (remote_client_bodies.h:1566) ==27271== by 0x4D199D3: virDomainPinVcpu (libvirt.c:8585) ==27271== by 0x4241F4: cmdVcpuPin (virsh.c:5262) ==27271== by 0x4150A6: vshCommandRun (virsh.c:17712) ==27271== Address 0x5602b80 is 0 bytes after a block of size 0 alloc'd ==27271== at 0x4A04A28: calloc (vg_replace_malloc.c:467) ==27271== by 0x4C89BDF: virAllocN (memory.c:129) ==27271== by 0x423868: _vshCalloc.clone.2 (virsh.c:454) ==27271== by 0x423EF9: cmdVcpuPin (virsh.c:5190) ==27271== by 0x4150A6: vshCommandRun (virsh.c:17712) ==27271== by 0x426583: main (virsh.c:19289) ==27271== ==27271== ==27271== 4 errors in context 2 of 2: ==27271== Invalid read of size 1 ==27271== at 0x424133: cmdVcpuPin (virsh.c:5245) ==27271== by 0x4150A6: vshCommandRun (virsh.c:17712) ==27271== by 0x426583: main (virsh.c:19289) ==27271== Address 0x5602b80 is 0 bytes after a block of size 0 alloc'd ==27271== at 0x4A04A28: calloc (vg_replace_malloc.c:467) ==27271== by 0x4C89BDF: virAllocN (memory.c:129) ==27271== by 0x423868: _vshCalloc.clone.2 (virsh.c:454) ==27271== by 0x423EF9: cmdVcpuPin (virsh.c:5190) ==27271== by 0x4150A6: vshCommandRun (virsh.c:17712) ==27271== by 0x426583: main (virsh.c:19289) Signed-off-by: Alex Jia&lt;ajia(a)redhat.com&gt; --- tools/virsh.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tools/virsh.c b/tools/virsh.c index 72ca93a..1613d2e 100644 --- a/tools/virsh.c +++ b/tools/virsh.c @@ -5187,7 +5187,7 @@ cmdVcpuPin(vshControl *ctl, const vshCmd *cmd) /* Pin mode: pinning specified vcpu to specified physical cpus*/ - cpumap = vshCalloc(ctl, 0, cpumaplen); + cpumap = vshCalloc(ctl, cpumaplen, sizeof(cpumap)); /* Parse cpulist */ cur = cpulist; if (*cur == 0) {