247cff335f
QubesVmCollection.save() overrides qubes.xml by creating new file, then
renaming it over the old one. If any process has that (old) file open
at the same time - especially while waiting on lock_db_for_writing() -
it will end up in accessing old, already unlinked file.
The exact calls would look like:
P1 P2
lock_db_for_writing
fd = open('qubes.xml')
fcntl(fd, F_SETLK, ...)
lock_db_for_writing
fd = open('qubes.xml')
fcntl(fd, F_SETLK, ...)
...
save():
open(temp-file)
write(temp-file, ...)
...
flush(temp-file)
rename(temp-file, 'qubes.xml')
close(fd) // close old file
lock_db_for_writing succeed
*** fd points at already unlinked
file
unlock_db
close(qubes.xml)
To fix that problem, added a check if (already locked) file is still the
same as qubes.xml.
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| core | ||
| core-modules | ||
| dispvm | ||
| doc | ||
| linux | ||
| qmemman | ||
| qubes-rpc | ||
| qubes-rpc-policy | ||
| qvm-tools | ||
| rpm_spec | ||
| site-packages | ||
| site-packages-qmemman | ||
| tests | ||
| xen-vm-config | ||
| .gitignore | ||
| LICENSE | ||
| Makefile | ||
| Makefile.builder | ||
| version | ||