diff options
Diffstat (limited to 'libraries/libvirt/patches/0003-blockjob-fix-use-after-free-in-blockcopy.patch')
| -rw-r--r-- | libraries/libvirt/patches/0003-blockjob-fix-use-after-free-in-blockcopy.patch | 105 |
1 files changed, 0 insertions, 105 deletions
diff --git a/libraries/libvirt/patches/0003-blockjob-fix-use-after-free-in-blockcopy.patch b/libraries/libvirt/patches/0003-blockjob-fix-use-after-free-in-blockcopy.patch deleted file mode 100644 index 0f967214e4..0000000000 --- a/libraries/libvirt/patches/0003-blockjob-fix-use-after-free-in-blockcopy.patch +++ /dev/null @@ -1,105 +0,0 @@ -From 9617e31b5349b193469874706abcbcb013e6a6fd Mon Sep 17 00:00:00 2001 -From: Eric Blake <eblake@redhat.com> -Date: Wed, 6 Aug 2014 14:06:23 -0600 -Subject: [PATCH 3/3] blockjob: fix use-after-free in blockcopy - -Commit febf84c2 tried to delay in-memory modification of the actual -domain disk structure until after the qemu event was received. -However, I missed that the code for block pivot had been temporarily -setting disk->src = disk->mirror prior to the qemu command, in order -to label the backing chain of a reused external blockcopy disk; -and calls into qemu while still in that state before finally undoing -things at the cleanup label. Since the qemu event handler then does: - virStorageSourceFree(disk->src); - disk->src = disk->mirror; -we have the sad race that a fast enough qemu event can cause a leak of -the original disk->src, as well as a use-after-free of the disk->mirror -contents, bad enough to crash libvirtd in some of my test runs, even -though the common case of the qemu event being much later won't trip -the race. - -I'll go wear the brown paper bag of shame, for introducing a crasher -in between rc1 and rc2 of the freeze for 1.2.7 :( My only -consolation is that virDomainBlockJobAbort requires the domain:write -ACL, so it is not a CVE. - -The valgrind report when the race occurs looks like: - -==25612== Invalid read of size 4 -==25612== at 0x50E7C90: virStorageSourceGetActualType (virstoragefile.c:1948) -==25612== by 0x209C0B18: qemuDomainDetermineDiskChain (qemu_domain.c:2473) -==25612== by 0x209D7F6A: qemuProcessHandleBlockJob (qemu_process.c:1087) -==25612== by 0x209F40C9: qemuMonitorEmitBlockJob (qemu_monitor.c:1357) -... -==25612== Address 0xe4b5610 is 0 bytes inside a block of size 200 free'd -==25612== at 0x4A07577: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) -==25612== by 0x50839E9: virFree (viralloc.c:582) -==25612== by 0x50E7E51: virStorageSourceFree (virstoragefile.c:2015) -==25612== by 0x209D7EFF: qemuProcessHandleBlockJob (qemu_process.c:1073) -==25612== by 0x209F40C9: qemuMonitorEmitBlockJob (qemu_monitor.c:1357) - -* src/qemu/qemu_driver.c (qemuDomainBlockPivot): Don't corrupt -disk->src, and only label chain for blockcopy. - -Signed-off-by: Eric Blake <eblake@redhat.com> -(cherry picked from commit 265680c58ebbee30bb70369e7d9905a599afbd6a) ---- - src/qemu/qemu_driver.c | 40 +++++++++++++++++++++++++--------------- - 1 file changed, 25 insertions(+), 15 deletions(-) - -diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c -index 57cc913..a050dbc 100644 ---- a/src/qemu/qemu_driver.c -+++ b/src/qemu/qemu_driver.c -@@ -14888,23 +14888,33 @@ qemuDomainBlockPivot(virConnectPtr conn, - } - } - -- /* We previously labeled only the top-level image; but if the -- * image includes a relative backing file, the pivot may result in -- * qemu needing to open the entire backing chain, so we need to -- * label the entire chain. This action is safe even if the -- * backing chain has already been labeled; but only necessary when -- * we know for sure that there is a backing chain. */ -- oldsrc = disk->src; -- disk->src = disk->mirror; -+ /* For active commit, the mirror is part of the already labeled -+ * chain. For blockcopy, we previously labeled only the top-level -+ * image; but if the user is reusing an external image that -+ * includes a backing file, the pivot may result in qemu needing -+ * to open the entire backing chain, so we need to label the -+ * entire chain. This action is safe even if the backing chain -+ * has already been labeled; but only necessary when we know for -+ * sure that there is a backing chain. */ -+ if (disk->mirrorJob == VIR_DOMAIN_BLOCK_JOB_TYPE_COPY) { -+ oldsrc = disk->src; -+ disk->src = disk->mirror; -+ -+ if (qemuDomainDetermineDiskChain(driver, vm, disk, false) < 0) -+ goto cleanup; - -- if (qemuDomainDetermineDiskChain(driver, vm, disk, false) < 0) -- goto cleanup; -+ if (disk->mirror->format && -+ disk->mirror->format != VIR_STORAGE_FILE_RAW && -+ (virDomainLockDiskAttach(driver->lockManager, cfg->uri, vm, -+ disk) < 0 || -+ qemuSetupDiskCgroup(vm, disk) < 0 || -+ virSecurityManagerSetDiskLabel(driver->securityManager, vm->def, -+ disk) < 0)) -+ goto cleanup; - -- if (disk->mirror->format && disk->mirror->format != VIR_STORAGE_FILE_RAW && -- (virDomainLockDiskAttach(driver->lockManager, cfg->uri, vm, disk) < 0 || -- qemuSetupDiskCgroup(vm, disk) < 0 || -- virSecurityManagerSetDiskLabel(driver->securityManager, vm->def, disk) < 0)) -- goto cleanup; -+ disk->src = oldsrc; -+ oldsrc = NULL; -+ } - - /* Attempt the pivot. Record the attempt now, to prevent duplicate - * attempts; but the actual disk change will be made when emitting --- -2.0.3 - |