From: David Howells <dhowells@redhat.com> stable inclusion from stable-v5.10.209 commit 4533e7623e6d206a6d8e67c9f8d242dd022accbb category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9TM8D CVE: CVE-2024-36031 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit acc657692aed438e9931438f8c923b2b107aebf9 upstream. Fix the size check added to dns_resolver_preparse() for the V1 server-list header so that it doesn't give EINVAL if the size supplied is the same as the size of the header struct (which should be valid). This can be tested with: echo -n -e '\0\0\01\xff\0\0' | keyctl padd dns_resolver desc @p which will give "add_key: Invalid argument" without this fix. Fixes: 1997b3cb4217 ("keys, dns: Fix missing size check of V1 server-list header") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Link: https://lore.kernel.org/r/ZZ4fyY4r3rqgZL+4@xpf.sh.intel.com/ Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Petr Vorel <pvorel@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yi Yang <yiyang13@huawei.com> --- net/dns_resolver/dns_key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c index 8324e9f97066..26a9d8434c23 100644 --- a/net/dns_resolver/dns_key.c +++ b/net/dns_resolver/dns_key.c @@ -104,7 +104,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep) const struct dns_server_list_v1_header *v1; /* It may be a server list. */ - if (datalen <= sizeof(*v1)) + if (datalen < sizeof(*v1)) return -EINVAL; v1 = (const struct dns_server_list_v1_header *)data; -- 2.25.1