Without rtnl_lock held, a hardif might be retrieved as primary interface of
a meshif, but then (while operating on this interface) getting decoupled
from the mesh interface. In this case, the meshif still exists but the
pointer from the primary hardif to the meshif is set to NULL.
The mesh_iface must be checked first to be non-NULL before continuing to
send an ARP request using meshif.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Reported-by: Ido Schimmel <idosch@nvidia.com>
Reported-by: syzbot+9fdcc9f05a98a540b816@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9fdcc9f05a98a540b816
Signed-off-by: Sven Eckelmann <sven@narfation.org>
The bla.num_requests is increased when no request_sent was in progress. And
it is decremented in various places (announcement was received, backbone is
purged, periodic work). But the check if the request_sent is actually set
to a specific state and the atomic_dec/_inc are not safe because they are
not atomic (TOCTOU) and multiple such code portions can run concurrently.
At the same time, it is necessary to modify request_sent (state) and
bla.num_requests atomically. Otherwise batadv_bla_send_request() might set
request_sent to 1 and is interrupted. batadv_handle_announce() can then
set request_sent back to 0 and decrement num_requests before
batadv_bla_send_request() incremented it.
The two operations must therefore be locked. And since state (request_sent)
and wait_periods are only accessed inside this lock, they can be converted
to simpler datatypes. And to avoid that the bla.num_requests is touched by
a parallel running context with a valid backbone_gw reference after
batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to
correctly signal that a backbone_gw is in the state of being cleaned up.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
but fails to properly handle their associated report_work:
- If report_work is running, the purge must wait for it to finish before
freeing the backbone_gw, otherwise the worker may access freed memory
(e.g. bat_priv).
- If report_work is pending, the purge must cancel it and release the
reference held for that pending work item.
The previous implementation called hlist_for_each_entry_safe() inside a
spin_lock_bh() section, but cancel_work_sync() may sleep and therefore
cannot be called from within a spinlock-protected region.
Restructure the loop to handle one entry per spinlock critical section:
acquire the lock, find the next entry to purge, remove it from the hash
list, then release the lock before calling cancel_work_sync() and
dropping the hash_entry reference. Repeat until no more entries require
purging.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Reviewed-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_bla_add_claim() fails to insert a new claim into the hash, it
leaked a reference to the backbone_gw for which the claim was intended.
Call batadv_backbone_gw_put() on the error path to release the reference
and avoid leaking the backbone_gw object.
Cc: stable@kernel.org
Fixes: 3db0decf11 ("batman-adv: Fix non-atomic bla_claim::backbone_gw access")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_bla_purge_claims() goes through the list of claims, it is only
traversing the hash list with an rcu_read_lock(). Due to a potential
parallel batadv_claim_put(), it can happen that it encounters a claim which
was actually in the process of being released+freed by
batadv_claim_release(). In this case, backbone_gw is set to NULL before the
delayed RCU kfree is started. Calling batadv_bla_claim_get_backbone_gw() is
then no longer allowed because it would cause a NULL-ptr derefence.
To avoid this, only claims with a valid reference counter must be purged.
All others are already taken care of.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
When batadv_bla_del_backbone_claims() removes all claims for a backbone, it
does this by dropping the link entry in the hash list. This list entry
itself was one of the references which need to be dropped at the same time
via batadv_claim_put().
But the batadv_claim_put() must not be done before the last access to the
claim object in this function. Otherwise the claim might be freed already
by the batadv_claim_release() function before the list entry was dropped.
Cc: stable@kernel.org
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Simon Wunderlich says:
====================
Here are two batman-adv bugfixes:
- reject oversized global TT response buffers, by Ruide Cao
- hold claim backbone gateways by reference, by Haoze Xie
* tag 'batadv-net-pullrequest-20260408' of https://git.open-mesh.org/linux-merge:
batman-adv: hold claim backbone gateways by reference
batman-adv: reject oversized global TT response buffers
====================
Link: https://patch.msgid.link/20260408110255.976389-1-sw@simonwunderlich.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
batadv_bla_add_claim() can replace claim->backbone_gw and drop the old
gateway's last reference while readers still follow the pointer.
The netlink claim dump path dereferences claim->backbone_gw->orig and
takes claim->backbone_gw->crc_lock without pinning the underlying
backbone gateway. batadv_bla_check_claim() still has the same naked
pointer access pattern.
Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate
on a stable gateway reference until the read-side work is complete.
This keeps the dump and claim-check paths aligned with the lifetime
rules introduced for the other BLA claim readers.
Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Fixes: 04f3f5bf18 ("batman-adv: add B.A.T.M.A.N. Dump BLA claims via netlink")
Cc: stable@vger.kernel.org
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Co-developed-by: Yuan Tan <yuantan098@gmail.com>
Signed-off-by: Yuan Tan <yuantan098@gmail.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Haoze Xie <royenheart@gmail.com>
Signed-off-by: Ao Zhou <n05ec@lzu.edu.cn>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Make batadv_bla_check_duplist() just use the new function skb_crc32c(),
instead of calling skb_seq_read() with crc32c(). This is faster and
simpler.
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The batadv_skb_crc32() helper was shared between Bridge Loop Avoidance and
Network Coding. With the removal of the network coding feature, it is
possible to just move this helper directly to Bridge Loop Avoidance.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The way how the virtual interface is called inside the batman-adv source
code is not consistent. The genl headers call it meshif and the rest of the
code calls is (mostly) softif.
The genl definitions cannot be touched because they are part of the UAPI.
But the rest of the batman-adv code can be touched to have a consistent
name again.
The bulk of the renaming was done using
sed -i -e 's/soft\(-\|\_\| \|\)i\([nf]\)/mesh\1i\2/g' \
-e 's/SOFT\(-\|\_\| \|\)I\([NF]\)/MESH\1I\2/g'
and then it was adjusted slightly when proofreading the changes.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Reduce duplicate code by using netlink helpers which return the
soft/hard interface directly. Instead of returning an interface index
which we are typically not interested in.
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The commit ea4692c75e ("lib/string_helpers: Consolidate string helpers
implementation") introduced common helpers to print string representations
of boolean helpers. These are supposed to be used instead of open coded
versions.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The commit 39ced19b9e ("lib/vsprintf: split out sprintf() and friends")
introduced a new header for the sprintf related functions which were
previously exposed via linux/kernel.h.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The commit d2a8ebbf81 ("kernel.h: split out container_of() and
typeof_member() macros") introduced a new header for the container_of
related macros from (previously) linux/kernel.h.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was
in wrong error handling in batadv_mesh_init().
Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case
of any batadv_*_init() calls failure. This approach may work well, when
there is some kind of indicator, which can tell which parts of batadv are
initialized; but there isn't any.
All written above lead to cleaning up uninitialized fields. Even if we hide
ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit
GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1]
To fix these bugs we can unwind batadv_*_init() calls one by one.
It is good approach for 2 reasons: 1) It fixes bugs on error handling
path 2) It improves the performance, since we won't call unneeded
batadv_*_free() functions.
So, this patch makes all batadv_*_init() clean up all allocated memory
before returning with an error to no call correspoing batadv_*_free()
and open-codes batadv_mesh_free() with proper order to avoid touching
uninitialized fields.
Link: https://lore.kernel.org/netdev/000000000000c87fbd05cef6bcb0@google.com/ [1]
Reported-and-tested-by: syzbot+28b0702ada0bf7381f58@syzkaller.appspotmail.com
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdev->dev_addr will be constant soon, make sure
the qualifier is propagated thru batman-adv.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The check if a batman-adv related object is NULL or not is now directly in
the batadv_*_put functions. It is not needed anymore to perform this check
outside these function:
The changes were generated using a coccinelle semantic patch:
@@
expression E;
@@
- if (likely(E != NULL))
(
batadv_backbone_gw_put
|
batadv_claim_put
|
batadv_dat_entry_put
|
batadv_gw_node_put
|
batadv_hardif_neigh_put
|
batadv_hardif_put
|
batadv_nc_node_put
|
batadv_nc_path_put
|
batadv_neigh_ifinfo_put
|
batadv_neigh_node_put
|
batadv_orig_ifinfo_put
|
batadv_orig_node_put
|
batadv_orig_node_vlan_put
|
batadv_softif_vlan_put
|
batadv_tp_vars_put
|
batadv_tt_global_entry_put
|
batadv_tt_local_entry_put
|
batadv_tt_orig_list_entry_put
|
batadv_tt_req_node_put
|
batadv_tvlv_container_put
|
batadv_tvlv_handler_put
)(E);
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The commit b37a466837 ("netdevice: add the case if dev is NULL") changed
the way how the NULL check for net_devices have to be handled when trying
to reduce its reference counter. Before this commit, it was the
responsibility of the caller to check whether the object is NULL or not.
But it was changed to behave more like kfree. Now the callee has to handle
the NULL-case.
The batman-adv code was scanned via cocinelle for similar places. These
were changed to use the paradigm
@@
identifier E, T, R, C;
identifier put;
@@
void put(struct T *E)
{
+ if (!E)
+ return;
kref_put(&E->C, R);
}
Functions which were used in other sources files were moved to the header
to allow the compiler to inline the NULL check and the kref_put call.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix some spelling mistakes in comments:
containg ==> containing
dont ==> don't
datas ==> data
brodcast ==> broadcast
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
