From 3a4d59e5cb35cf2395cfd8004dd16d45dd889e11 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Thu, 5 Dec 2019 16:35:51 +0100 Subject: [PATCH] extensions: among: Check call to fstat() If this fails, a bogus length value may be passed to mmap(). Fixes: 26753888720d8 ("nft: bridge: Rudimental among extension support") (cherry picked from commit 25b38bcbf2fdc019f438805c7d1ecd877af9c968) Signed-off-by: Phil Sutter --- extensions/libebt_among.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/extensions/libebt_among.c b/extensions/libebt_among.c index 2e87db3bc06fa..715d559f432c2 100644 --- a/extensions/libebt_among.c +++ b/extensions/libebt_among.c @@ -6,6 +6,7 @@ * August, 2003 */ +#include #include #include #include @@ -137,7 +138,10 @@ static int bramong_parse(int c, char **argv, int invert, if ((fd = open(optarg, O_RDONLY)) == -1) xtables_error(PARAMETER_PROBLEM, "Couldn't open file '%s'", optarg); - fstat(fd, &stats); + if (fstat(fd, &stats) < 0) + xtables_error(PARAMETER_PROBLEM, + "fstat(%s) failed: '%s'", + optarg, strerror(errno)); flen = stats.st_size; /* use mmap because the file will probably be big */ optarg = mmap(0, flen, PROT_READ | PROT_WRITE, -- 2.24.0