Commit Graph

26 Commits

Author SHA1 Message Date
Willem de Bruijn
7b3ba18703 llc: verify mac len before reading mac header
LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.

Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).

    BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
    BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
    llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
    llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
    llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
    __netif_receive_skb_one_core net/core/dev.c:5523 [inline]
    __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637
    netif_receive_skb_internal net/core/dev.c:5723 [inline]
    netif_receive_skb+0x58/0x660 net/core/dev.c:5782
    tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
    tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002

Add a mac_len test before all three eth_hdr(skb) calls under net/llc.

There are further uses in include/net/llc_pdu.h. All these are
protected by a test skb->protocol == ETH_P_802_2. Which does not
protect against this tun scenario.

But the mac_len test added in this patch in llc_fixup_skb will
indirectly protect those too. That is called from llc_rcv before any
other LLC code.

It is tempting to just add a blanket mac_len check in llc_rcv, but
not sure whether that could break valid LLC paths that do not assume
an Ethernet header. 802.2 LLC may be used on top of non-802.3
protocols in principle. The below referenced commit shows that used
to, on top of Token Ring.

At least one of the three eth_hdr uses goes back to before the start
of git history. But the one that syzbot exercises is introduced in
this commit. That commit is old enough (2008), that effectively all
stable kernels should receive this.

Fixes: f83f1768f8 ("[LLC]: skb allocation size for responses")
Reported-by: syzbot+a8c7be6dee0de1b669cc@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20231025234251.3796495-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-01 22:21:32 -07:00
Jiapeng Chong
2342eb1afe llc2: Remove redundant assignment to rc
Variable rc is set to zero but this value is never read as it is
overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

net/llc/llc_station.c:86:2: warning: Value stored to 'rc' is never read
[clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-27 14:16:14 -07:00
Chan Shu Tak, Alex
af1c0e4e00 llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c)
When a frame with NULL DSAP is received, llc_station_rcv is called.
In turn, llc_stat_ev_rx_null_dsap_xid_c is called to check if it is a NULL
XID frame. The return statement of llc_stat_ev_rx_null_dsap_xid_c returns 1
when the incoming frame is not a NULL XID frame and 0 otherwise. Hence, a
NULL XID response is returned unexpectedly, e.g. when the incoming frame is
a NULL TEST command.

To fix the error, simply remove the conditional operator.

A similar error in llc_stat_ev_rx_null_dsap_test_c is also fixed.

Signed-off-by: Chan Shu Tak, Alex <alexchan@task.com.hk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-20 21:19:36 -08:00
Ben Hutchings
12ebc8b9af llc2: Collapse remainder of state machine into simple if-else if-statement
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:19 -04:00
Ben Hutchings
da31888018 llc2: Remove explicit indexing of state action arrays
These arrays are accessed by iteration in
llc_exec_station_trans_actions().  There must not be any zero-filled
gaps in them, so the explicit indices are pointless.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:19 -04:00
Ben Hutchings
5ecf9eea26 llc2: Remove the station send queue
We only ever put one skb on the send queue, and then immediately
send it.  Remove the queue and call dev_queue_xmit() directly.

This leaves struct llc_station empty, so remove that as well.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:18 -04:00
Ben Hutchings
04d191c259 llc2: Collapse the station event receive path
We only ever put one skb on the event queue, and then immediately
process it.  Remove the queue and fold together the related functions,
removing several blatantly false comments.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:18 -04:00
Ben Hutchings
025e363325 llc2: Remove dead code for state machine
The initial state is UP and there is no way to enter the other states
as the required event type is never generated.  Delete all states,
event types, and other dead code.  The only thing left is handling
of the XID and TEST commands.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:18 -04:00
Ben Hutchings
cc6328dfe4 llc2: Remove pointless indirection through llc_stat_state_trans_end
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-17 13:04:18 -04:00
Ben Hutchings
aadf31de16 llc: Fix races between llc2 handler use and (un)registration
When registering the handlers, any state they rely on must be
completely initialised first.  When unregistering, we must wait until
they are definitely no longer running.  llc_rcv() must also avoid
reading the handler pointers again after checking for NULL.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 16:52:02 -07:00
Ben Hutchings
f4f8720feb llc2: Call llc_station_exit() on llc2_init() failure path
Otherwise the station packet handler will remain registered even though
the module is unloaded.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 16:51:40 -07:00
Ben Hutchings
6024935f5f llc2: Fix silent failure of llc_station_init()
llc_station_init() creates and processes an event skb with no effect
other than to change the state from DOWN to UP.  Allocation failure is
reported, but then ignored by its caller, llc2_init().  Remove this
possibility by simply initialising the state as UP.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-14 16:51:18 -07:00
Sorin Dumitru
91d27a8650 llc: free the right skb
We are freeing skb instead of nskb, resulting in a double
free on skb and a leak from nskb.

Signed-off-by: Sorin Dumitru <sdumitru@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-06 13:30:01 -07:00
Ben Hutchings
2c53040f01 net: Fix (nearly-)kernel-doc comments for various functions
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
Dan Carpenter
2507136f74 net/llc: storing negative error codes in unsigned short
If the alloc_skb() fails then we return 65431 instead of -ENOBUFS
(-105).

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-16 22:38:23 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Joonwoo Park
f83f1768f8 [LLC]: skb allocation size for responses
Allocate the skb for llc responses with the received packet size by
using the size adjustable llc_frame_alloc.
Don't allocate useless extra payload.
Cleanup magic numbers.

So, this fixes oops.
Reported by Jim Westfall:
kernel: skb_over_panic: text:c0541fc7 len:1000 put:997 head:c166ac00 data:c166ac2f tail:0xc166b017 end:0xc166ac80 dev:eth0
kernel: ------------[ cut here ]------------
kernel: kernel BUG at net/core/skbuff.c:95!

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-31 21:02:47 -07:00
Joonwoo Park
a5a04819c5 [LLC]: station source mac address
kill unnecessary llc_station_mac_sa.

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-28 16:28:36 -07:00
Pavel Emelyanov
b24b8a247f [NET]: Convert init_timer into setup_timer
Many-many code in the kernel initialized the timer->function
and  timer->data together with calling init_timer(timer). There
is already a helper for this. Use it for networking code.

The patch is HUGE, but makes the code 130 lines shorter
(98 insertions(+), 228 deletions(-)).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:35 -08:00
YOSHIFUJI Hideaki
d57b1869b2 [NET] LLC: Fix whitespace errors.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:19:53 -08:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Arnaldo Carvalho de Melo
d389424e00 [LLC]: Fix the accept path
Borrowing the structure of TCP/IP for this. On the receive of new connections I
was bh_lock_socking the _new_ sock, not the listening one, duh, now it survives
the ssh connections storm I've been using to test this specific bug.

Also fixes send side skb sock accounting.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-09-22 07:57:21 -03:00
Arnaldo Carvalho de Melo
249ff1c6d3 [LLC]: Use some more likely/unlikely
Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-09-22 04:32:10 -03:00
Arnaldo Carvalho de Melo
590232a715 [LLC]: Add sysctl support for the LLC timeouts
Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-09-22 04:30:44 -03:00
Arnaldo Carvalho de Melo
1d67e6501b [LLC]: Make llc_frame_alloc take a net_device as an argument
So as to set the newly created sk_buff ->dev member with it, that way we stop
using dev_base->next, that is the wrong thing to do, as there may well be
several interfaces being used with LLC. This was not such a big problem after
all as most of the users of llc_alloc_frame were setting the correct dev, but
this way code is reduced.

This also fixes another bug in llc_station_ac_send_null_dsap_xid_c, that was
not setting the skb->dev field.

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-09-22 03:27:56 -03:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00