4.14-stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Vyukov dvyukov@google.com
[ Upstream commit 1e98ffea5a8935ec040ab72299e349cb44b8defd ]
Several netfilter matches and targets put kernel pointers into info objects, but don't set usersize in descriptors. This leads to kernel pointer leaks if a match/target is set and then read back to userspace.
Properly set usersize for these matches/targets.
Found with manual code inspection.
Fixes: ec2318904965 ("xtables: extend matches and targets with .usersize") Signed-off-by: Dmitry Vyukov dvyukov@google.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/xt_IDLETIMER.c | 1 + net/netfilter/xt_LED.c | 1 + net/netfilter/xt_limit.c | 3 +-- net/netfilter/xt_nfacct.c | 1 + net/netfilter/xt_statistic.c | 1 + 5 files changed, 5 insertions(+), 2 deletions(-)
--- a/net/netfilter/xt_IDLETIMER.c +++ b/net/netfilter/xt_IDLETIMER.c @@ -256,6 +256,7 @@ static struct xt_target idletimer_tg __r .family = NFPROTO_UNSPEC, .target = idletimer_tg_target, .targetsize = sizeof(struct idletimer_tg_info), + .usersize = offsetof(struct idletimer_tg_info, timer), .checkentry = idletimer_tg_checkentry, .destroy = idletimer_tg_destroy, .me = THIS_MODULE, --- a/net/netfilter/xt_LED.c +++ b/net/netfilter/xt_LED.c @@ -198,6 +198,7 @@ static struct xt_target led_tg_reg __rea .family = NFPROTO_UNSPEC, .target = led_tg, .targetsize = sizeof(struct xt_led_info), + .usersize = offsetof(struct xt_led_info, internal_data), .checkentry = led_tg_check, .destroy = led_tg_destroy, .me = THIS_MODULE, --- a/net/netfilter/xt_limit.c +++ b/net/netfilter/xt_limit.c @@ -193,9 +193,8 @@ static struct xt_match limit_mt_reg __re .compatsize = sizeof(struct compat_xt_rateinfo), .compat_from_user = limit_mt_compat_from_user, .compat_to_user = limit_mt_compat_to_user, -#else - .usersize = offsetof(struct xt_rateinfo, prev), #endif + .usersize = offsetof(struct xt_rateinfo, prev), .me = THIS_MODULE, };
--- a/net/netfilter/xt_nfacct.c +++ b/net/netfilter/xt_nfacct.c @@ -62,6 +62,7 @@ static struct xt_match nfacct_mt_reg __r .match = nfacct_mt, .destroy = nfacct_mt_destroy, .matchsize = sizeof(struct xt_nfacct_match_info), + .usersize = offsetof(struct xt_nfacct_match_info, nfacct), .me = THIS_MODULE, };
--- a/net/netfilter/xt_statistic.c +++ b/net/netfilter/xt_statistic.c @@ -84,6 +84,7 @@ static struct xt_match xt_statistic_mt_r .checkentry = statistic_mt_check, .destroy = statistic_mt_destroy, .matchsize = sizeof(struct xt_statistic_info), + .usersize = offsetof(struct xt_statistic_info, master), .me = THIS_MODULE, };