Commit graph

4 commits

Author SHA1 Message Date
David Howells
0b6295685f keys, dns: Fix size check of V1 server-list header
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>
2024-11-18 12:12:43 +01:00
Edward Adam Davis
2c44baceb8 keys, dns: Fix missing size check of V1 server-list header
commit 1997b3cb4217b09e49659b634c94da47f0340409 upstream.

The dns_resolver_preparse() function has a check on the size of the
payload for the basic header of the binary-style payload, but is missing
a check for the size of the V1 server-list payload header after
determining that's what we've been given.

Fix this by getting rid of the the pointer to the basic header and just
assuming that we have a V1 server-list payload and moving the V1 server
list pointer inside the if-statement.  Dealing with other types and
versions can be left for when such have been defined.

This can be tested by doing the following with KASAN enabled:

    echo -n -e '\x0\x0\x1\x2' | keyctl padd dns_resolver foo @p

and produces an oops like the following:

    BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
    Read of size 1 at addr ffff888028894084 by task syz-executor265/5069
    ...
    Call Trace:
      dns_resolver_preparse+0xc9f/0xd60 net/dns_resolver/dns_key.c:127
      __key_create_or_update+0x453/0xdf0 security/keys/key.c:842
      key_create_or_update+0x42/0x50 security/keys/key.c:1007
      __do_sys_add_key+0x29c/0x450 security/keys/keyctl.c:134
      do_syscall_x64 arch/x86/entry/common.c:52 [inline]
      do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
      entry_SYSCALL_64_after_hwframe+0x62/0x6a

This patch was originally by Edward Adam Davis, but was modified by
Linus.

Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
Reported-and-tested-by: syzbot+94bbb75204a05da3d89f@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/0000000000009b39bc060c73e209@google.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Cc: Edward Adam Davis <eadavis@qq.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jeffrey E Altman <jaltman@auristor.com>
Cc: Wang Lei <wang840925@gmail.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Steve French <sfrench@us.ibm.com>
Cc: Marc Dionne <marc.dionne@auristor.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jeffrey E Altman <jaltman@auristor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-18 12:12:05 +01:00
David Howells
9f7c624928 keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry
[ Upstream commit 39299bdd2546688d92ed9db4948f6219ca1b9542 ]

If a key has an expiration time, then when that time passes, the key is
left around for a certain amount of time before being collected (5 mins by
default) so that EKEYEXPIRED can be returned instead of ENOKEY.  This is a
problem for DNS keys because we want to redo the DNS lookup immediately at
that point.

Fix this by allowing key types to be marked such that keys of that type
don't have this extra period, but are reclaimed as soon as they expire and
turn this on for dns_resolver-type keys.  To make this easier to handle,
key->expiry is changed to be permanent if TIME64_MAX rather than 0.

Furthermore, give such new-style negative DNS results a 1s default expiry
if no other expiry time is set rather than allowing it to stick around
indefinitely.  This shouldn't be zero as ls will follow a failing stat call
immediately with a second with AT_SYMLINK_NOFOLLOW added.

Fixes: 1a4240f4764a ("DNS: Separate out CIFS DNS Resolver code")
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: Wang Lei <wang840925@gmail.com>
cc: Jeff Layton <jlayton@redhat.com>
cc: Steve French <smfrench@gmail.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jarkko Sakkinen <jarkko@kernel.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: linux-afs@lists.infradead.org
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: keyrings@vger.kernel.org
cc: netdev@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 12:11:59 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00