From d06037bc128d646f0addca86a268205c0e3ad5d8 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 2 Jul 2019 14:17:00 -0700 Subject: crypto: user - prevent operating on larval algorithms commit 21d4120ec6f5b5992b01b96ac484701163917b63 upstream. Michal Suchanek reported [1] that running the pcrypt_aead01 test from LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of alg->cra_users.next in crypto_remove_spawns(), via crypto_del_alg(). The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG. The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to unregister isn't a real registered algorithm, but rather is a "test larval", which is a special "algorithm" added to the algorithms list while the real algorithm is still being tested. Larvals don't have initialized cra_users, so that causes the crash. Normally pcrypt_aead01 doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted. Everything else in the "crypto user configuration" API has this same bug too, i.e. it inappropriately allows operating on larval algorithms (though it doesn't look like the other cases can cause a crash). Fix this by making crypto_alg_match() exclude larval algorithms. [1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de [2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c Reported-by: Michal Suchanek Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Cc: # v3.2+ Cc: Steffen Klassert Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/crypto_user.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'crypto/crypto_user.c') diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index b5758768920b..2b8fb8f1391e 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -55,6 +55,9 @@ static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) list_for_each_entry(q, &crypto_alg_list, cra_list) { int match = 0; + if (crypto_is_larval(q)) + continue; + if ((q->cra_flags ^ p->cru_type) & p->cru_mask) continue; -- cgit v1.2.3 From d98de9d9b8427db4be1b91949cc633aab5f7e76a Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Thu, 6 Dec 2018 15:55:41 -0800 Subject: crypto: user - support incremental algorithm dumps [ Upstream commit 0ac6b8fb23c724b015d9ca70a89126e8d1563166 ] CRYPTO_MSG_GETALG in NLM_F_DUMP mode sometimes doesn't return all registered crypto algorithms, because it doesn't support incremental dumps. crypto_dump_report() only permits itself to be called once, yet the netlink subsystem allocates at most ~64 KiB for the skb being dumped to. Thus only the first recvmsg() returns data, and it may only include a subset of the crypto algorithms even if the user buffer passed to recvmsg() is large enough to hold all of them. Fix this by using one of the arguments in the netlink_callback structure to keep track of the current position in the algorithm list. Then userspace can do multiple recvmsg() on the socket after sending the dump request. This is the way netlink dumps work elsewhere in the kernel; it's unclear why this was different (probably just an oversight). Also fix an integer overflow when calculating the dump buffer size hint. Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- crypto/crypto_user.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) (limited to 'crypto/crypto_user.c') diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 2b8fb8f1391e..5e457a7dd1c9 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -296,30 +296,33 @@ drop_alg: static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) { - struct crypto_alg *alg; + const size_t start_pos = cb->args[0]; + size_t pos = 0; struct crypto_dump_info info; - int err; - - if (cb->args[0]) - goto out; - - cb->args[0] = 1; + struct crypto_alg *alg; + int res; info.in_skb = cb->skb; info.out_skb = skb; info.nlmsg_seq = cb->nlh->nlmsg_seq; info.nlmsg_flags = NLM_F_MULTI; + down_read(&crypto_alg_sem); list_for_each_entry(alg, &crypto_alg_list, cra_list) { - err = crypto_report_alg(alg, &info); - if (err) - goto out_err; + if (pos >= start_pos) { + res = crypto_report_alg(alg, &info); + if (res == -EMSGSIZE) + break; + if (res) + goto out; + } + pos++; } - + cb->args[0] = pos; + res = skb->len; out: - return skb->len; -out_err: - return err; + up_read(&crypto_alg_sem); + return res; } static int crypto_dump_report_done(struct netlink_callback *cb) @@ -503,7 +506,7 @@ static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && (nlh->nlmsg_flags & NLM_F_DUMP))) { struct crypto_alg *alg; - u16 dump_alloc = 0; + unsigned long dump_alloc = 0; if (link->dump == NULL) return -EINVAL; @@ -511,16 +514,16 @@ static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, down_read(&crypto_alg_sem); list_for_each_entry(alg, &crypto_alg_list, cra_list) dump_alloc += CRYPTO_REPORT_MAXSIZE; + up_read(&crypto_alg_sem); { struct netlink_dump_control c = { .dump = link->dump, .done = link->done, - .min_dump_alloc = dump_alloc, + .min_dump_alloc = min(dump_alloc, 65535UL), }; err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); } - up_read(&crypto_alg_sem); return err; } -- cgit v1.2.3 From 41b3b8e0775465c33083ce1998df7f15c039c9bf Mon Sep 17 00:00:00 2001 From: Navid Emamdoost Date: Fri, 4 Oct 2019 14:29:16 -0500 Subject: crypto: user - fix memory leak in crypto_report commit ffdde5932042600c6807d46c1550b28b0db6a3bc upstream. In crypto_report, a new skb is created via nlmsg_new(). This skb should be released if crypto_report_alg() fails. Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Cc: Signed-off-by: Navid Emamdoost Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/crypto_user.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'crypto/crypto_user.c') diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 5e457a7dd1c9..b6899be8065d 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -288,8 +288,10 @@ static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, drop_alg: crypto_mod_put(alg); - if (err) + if (err) { + kfree_skb(skb); return err; + } return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid); } -- cgit v1.2.3