[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 for-4.9 2/5] hvm/dmop: Make copy_buf_{from, to}_guest for a buffer not big enough an error.
From: Jennifer Herbert <jennifer.herbert@xxxxxxxxxx> This makes copying to or from a buf that isn't big enough an error. If the buffer isnt big enough, trying to carry on regardless can only cause trouble later on. Signed-off-by: Jennifer Herbert <Jennifer.Herbert@xxxxxxxxxx> -- CC: Paul Durrant <paul.durrant@xxxxxxxxxx> CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CC: Jan Beulich <JBeulich@xxxxxxxx> CC: Julien Grall <julien.grall@xxxxxxx> --- Switch buf_bytes to {dst, src}_bytes for copy_{from,to}_guest --- xen/arch/x86/hvm/dm.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c index e583e41..89186d2 100644 --- a/xen/arch/x86/hvm/dm.c +++ b/xen/arch/x86/hvm/dm.c @@ -36,30 +36,32 @@ static bool copy_buf_from_guest(const xen_dm_op_buf_t bufs[], unsigned int nr_bufs, void *dst, unsigned int idx, size_t dst_size) { - size_t size; + size_t buf_bytes; if ( idx >= nr_bufs ) return false; - memset(dst, 0, dst_size); - - size = min_t(size_t, dst_size, bufs[idx].size); + buf_bytes = bufs[idx].size; + if ( dst_size > buf_bytes ) + return false; - return !copy_from_guest(dst, bufs[idx].h, size); + return !copy_from_guest(dst, bufs[idx].h, dst_size); } static bool copy_buf_to_guest(const xen_dm_op_buf_t bufs[], unsigned int nr_bufs, unsigned int idx, const void *src, size_t src_size) { - size_t size; + size_t buf_bytes; if ( idx >= nr_bufs ) return false; - size = min_t(size_t, bufs[idx].size, src_size); + buf_bytes = bufs[idx].size; + if ( src_size > buf_bytes ) + return false; - return !copy_to_guest(bufs[idx].h, src, size); + return !copy_to_guest(bufs[idx].h, src, src_size); } static int track_dirty_vram(struct domain *d, xen_pfn_t first_pfn, -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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