Replay data is not considered a possible attack vector; add a model that
does not use getc so that "tainted data" warnings are suppressed.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180514141218.28438-1-pbonzini@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Whitespace tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Commit eb7eeb8 ("memory: split address_space_read and
address_space_write", 2015-12-17) made address_space_rw
dispatch to one of address_space_read or address_space_write,
rather than vice versa.
For callers of address_space_read and address_space_write this
causes false positive defects when Coverity sees a length-8 write in
address_space_read and a length-4 (e.g. int*) buffer to read into.
As long as the size of the buffer is okay, this is a false positive.
Reflect the code change into the model.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170315081641.20588-1-pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
We model all the non-deprecated memory allocation functions from
https://developer.gnome.org/glib/stable/glib-Memory-Allocation.html
except for g_memdup(), g_clear_pointer(), g_steal_pointer(). We don't
use the latter two. Model the former.
Coverity now reports an OVERRUN
vl.c:2317: alloc_strlen: Allocating insufficient memory for the terminating null of the string.
Correct, but we omit the terminating null intentionally there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1448901152-11716-1-git-send-email-armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In my testing, Coverity reported two more CHECKED_RETURN:
* qemu-char.c:1248: fixed in commit c1f2448: "qemu-char: retry g_poll
on EINTR".
* migration/qemu-file-unix.c:75: harmless, cleaned up in commit
4e39f57 "migration: Clean up use of g_poll() in
socket_writev_buffer()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1450336833-27710-1-git-send-email-armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If the is_write argument is true, address_space_rw writes to memory
and thus reads from the buffer. The opposite holds if is_write is
false. Fix the model.
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Make address_space_rw take transaction attributes, rather
than always using the 'unspecified' attributes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Memory allocated with GLib needs to be freed with GLib. Freeing it
with free() instead of g_free() is a common error. Harmless when
g_free() is a trivial wrapper around free(), which is commonly the
case. But model the difference anyway.
In a local scan, this flags four ALLOC_FREE_MISMATCH. Requires
--enable ALLOC_FREE_MISMATCH, because the checker is still preview.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Without a model, Coverity can't know that the result of g_strdup()
needs to be fed to g_free().
One way to get such a model is to scan GLib, build a derived model
file with cov-collect-models, and use that when scanning QEMU.
Unfortunately, the Coverity Scan service we use doesn't support that.
Thus, we're stuck with the other way: write a user model. Doing that
for all of GLib is hardly practical. I'm doing it for the "String
Utility Functions" we actually use that return dynamically allocated
strings.
In a local scan, this flags 20 additional RESOURCE_LEAKs. The ones I
checked look genuine.
It also loses a NULL_RETURNS about ppce500_init() using
qemu_find_file() without error checking. I don't understand why.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
In current versions of GLib, g_new() may expand into g_malloc_n().
When it does, Coverity can't see the memory allocation, because we
don't model g_malloc_n(). Similarly for g_new0(), g_renew(),
g_try_new(), g_try_new0(), g_try_renew().
Model g_malloc_n(), g_malloc0_n(), g_realloc_n(). Model
g_try_malloc_n(), g_try_malloc0_n(), g_try_realloc_n() by adding
indeterminate out of memory conditions on top.
To avoid undue duplication, replace the existing models for g_malloc()
& friends by trivial wrappers around g_malloc_n() & friends.
In a local scan, this flags four additional RESOURCE_LEAKs and one
NULL_RETURNS.
The NULL_RETURNS is a false positive: Coverity can now see that
g_try_malloc(l1_sz * sizeof(uint64_t)) in
qcow2_check_metadata_overlap() may return NULL, but is too stupid to
recognize that a loop executing l1_sz times won't be entered then.
Three out of the four RESOURCE_LEAKs appear genuine. The false
positive is in ppce500_prep_device_tree(): the pointer dies, but a
pointer to a struct member escapes, and we get the pointer back for
freeing with container_of(). Too funky for Coverity.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
This is the model file that is being used for the QEMU project's scans
on scan.coverity.com. It fixed about 30 false positives (10% of the
total) and exposed about 60 new memory leaks.
The file is not automatically used; changes to it must be propagated
to the website manually by an admin (right now Markus, Peter and me
are admins).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
