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| author | Mark Johnston <markj@FreeBSD.org> | 2021-03-25 21:55:20 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2021-03-28 00:24:15 +0000 |
| commit | c7d10e7ec872070a40bbddc3158b1997c1df09af (patch) | |
| tree | c0379188a320bf25591dac2c8ada079991049557 | |
| parent | 41a8dc361969629706827fb867cedaec3c270e68 (diff) | |
| download | src-c7d10e7ec872070a40bbddc3158b1997c1df09af.tar.gz src-c7d10e7ec872070a40bbddc3158b1997c1df09af.zip | |
accept_filter: Fix filter parameter handling
For filters which implement accf_create, the setsockopt(2) handler
caches the filter name in the socket, but it also incorrectly frees the
buffer containing the copy, leaving a dangling pointer. Note that no
accept filters provided in the base system are susceptible to this, as
they don't implement accf_create.
Reported by: Alexey Kulaev <alex.qart@gmail.com>
Discussed with: emaste
Security: kernel use-after-free
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
(cherry picked from commit 653a437c04440495cd8e7712c7cf39444f26f1ee)
| -rw-r--r-- | sys/kern/uipc_accf.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sys/kern/uipc_accf.c b/sys/kern/uipc_accf.c index debf4b2deeb1..3ca64dd21e25 100644 --- a/sys/kern/uipc_accf.c +++ b/sys/kern/uipc_accf.c @@ -299,6 +299,7 @@ accept_filt_setopt(struct socket *so, struct sockopt *sopt) so->sol_accept_filter = afp; so->sol_accept_filter_arg = accept_filter_arg; so->sol_accept_filter_str = accept_filter_str; + accept_filter_str = NULL; so->so_options |= SO_ACCEPTFILTER; out: SOCK_UNLOCK(so); |