Commit 57b0e314 authored Nov 03, 2018 by Eric Biggers Committed by Linus Torvalds Jan 01, 2019

KEYS: fix parsing invalid pkey info string



We need to check the return value of match_token() for Opt_err before
doing anything with it.

[ Not only did the old "-1" value for Opt_err cause problems for the
  __test_and_set_bit(), as fixed in commit 94c13f66 ("security:
  don't use a negative Opt_err token index"), but accessing
  "args[0].from" is invalid for the Opt_err case, as pointed out by Eric
  later.  - Linus ]

Reported-by:  <syzbot+a22e0dc07567662c50bc@syzkaller.appspotmail.com>
Fixes: 00d60fd3 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: stable@kernel.org # 4.20
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e1ef035d

security/keys/keyctl_pkey.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,8 @@ static int keyctl_pkey_params_parse(struct kernel_pkey_params *params)
		if (p == '\0' \|\| p == ' ' \|\| *p == '\t')
		continue;
		token = match_token(p, param_keys, args);
		if (token == Opt_err)
		return -EINVAL;
		if (__test_and_set_bit(token, &token_mask))
		return -EINVAL;
		q = args[0].from;