Re: [Libguestfs] [libnbd PATCH] info: Keep request within 4G bound

Otherwise, we get a failure due to Numerical result out of range. And for safety's sake, we are best capping our request to an aligned value, if the server insists on minimum alignment. Fixes: f3fd935c --- info/nbdinfo.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/info/nbdinfo.c b/info/nbdinfo.c index 1afdf98..2b22f51 100644 --- a/info/nbdinfo.c +++ b/info/nbdinfo.c @@ -31,6 +31,8 @@ #include <libnbd.h> +#define MIN(a,b) ((a) < (b) ? (a) : (b))

static const char *progname; static FILE *fp; static bool list_all = false; @@ -267,7 +269,7 @@ main (int argc, char *argv[]) fprintf (fp, "%" PRIi64 "\n", size); } else if (map) { /* --map (!list_all) */ - uint64_t offset, prev_offset; + uint64_t offset, prev_offset, align, max_len; /* Did we get the requested map? */ if (!nbd_can_meta_context (nbd, map)) { @@ -276,6 +278,8 @@ main (int argc, char *argv[]) progname, map); exit (EXIT_FAILURE); } + align = nbd_get_block_size (nbd, LIBNBD_SIZE_MINIMUM) ?: 512; + max_len = UINT32_MAX - align + 1; size = nbd_get_size (nbd); if (size == -1) { @@ -286,7 +290,7 @@ main (int argc, char *argv[]) if (json_output) fprintf (fp, "[\n"); for (offset = 0; offset < size;) { prev_offset = offset; - if (nbd_block_status (nbd, size - offset, offset, + if (nbd_block_status (nbd, MIN (size - offset, max_len), offset, (nbd_extent_callback) { .callback = extent_callback, .user_data = &offset }, 0) == -1) { -- 2.29.0.rc1