With -Wsign-compare, compilers warn about a mismatching signedness in a comparison in fdt_resize(). A negative buffer size will surely do us no good, so let's rule this case out first. In the actual comparison we then know that a cast to an unsigned type is safe. Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> --- libfdt/fdt_sw.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libfdt/fdt_sw.c b/libfdt/fdt_sw.c index 8a76adf..4c62922 100644 --- a/libfdt/fdt_sw.c +++ b/libfdt/fdt_sw.c @@ -152,6 +152,9 @@ int fdt_resize(void *fdt, void *buf, int bufsize) FDT_SW_PROBE(fdt); + if (bufsize < 0) + return -FDT_ERR_NOSPACE; + headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); tailsize = fdt_size_dt_strings(fdt); @@ -159,7 +162,7 @@ int fdt_resize(void *fdt, void *buf, int bufsize) headsize + tailsize > fdt_totalsize(fdt)) return -FDT_ERR_INTERNAL; - if ((headsize + tailsize) > bufsize) + if ((headsize + tailsize) > (unsigned)bufsize) return -FDT_ERR_NOSPACE; oldtail = (char *)fdt + fdt_totalsize(fdt) - tailsize; -- 2.17.5
