kernel/linux.git/net/can/raw.c, branch linux-7.0.y

can: raw: fix ro->uniq use-after-free in raw_rcv()

2026-04-22T11:32:15+00:00

commit a535a9217ca3f2fccedaafb2fddb4c48f27d36dc upstream. raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. Fixes: 514ac99c64b2 ("can: fix multiple delivery of a single CAN frame for overlapping CAN filters") Cc: stable@vger.kernel.org # v4.1+ Assisted-by: Bynario AI Signed-off-by: Samuel Page Link: https://patch.msgid.link/26ec626d-cae7-4418-9782-7198864d070c@bynar.io Acked-by: Oliver Hartkopp [mkl: applied manually] Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: remove private CAN skb headroom infrastructure

2026-02-05T10:58:40+00:00

This patch removes struct can_skb_priv which was stored at skb->head and the can_skb_reserve() helper which was used to shift skb->head. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-5-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: move ifindex to CAN skb extensions

2026-02-05T10:58:40+00:00

When routing CAN frames over different CAN interfaces the interface index skb->iif is overwritten with every single hop. To prevent sending a CAN frame back to its originating (first) incoming CAN interface another ifindex variable is needed, which was stored in can_skb_priv::ifindex. Move the can_skb_priv::ifindex content to can_skb_ext::can_iif. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-3-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: add CAN skb extension infrastructure

2026-02-05T10:58:39+00:00

To remove the private CAN bus skb headroom infrastructure 8 bytes need to be stored in the skb. The skb extensions are a common pattern and an easy and efficient way to hold private data travelling along with the skb. We only need the skb_ext_add() and skb_ext_find() functions to allocate and access CAN specific content as the skb helpers to copy/clone/free skbs automatically take care of skb extensions and their final removal. This patch introduces the complete CAN skb extensions infrastructure: - add struct can_skb_ext in new file include/net/can.h - add include/net/can.h in MAINTAINERS - add SKB_EXT_CAN to skbuff.c and skbuff.h - select SKB_EXTENSIONS in Kconfig when CONFIG_CAN is enabled - check for existing CAN skb extensions in can_rcv() in af_can.c - add CAN skb extensions allocation at every skb_alloc() location - duplicate the skb extensions if cloning outgoing skbs (framelen/gw_hops) - introduce can_skb_ext_add() and can_skb_ext_find() helpers The patch also corrects an indention issue in the original code from 2018: Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202602010426.PnGrYAk3-lkp@intel.com/ Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-2-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: use skb hash instead of private variable in headroom

2026-02-05T10:58:39+00:00

The can_skb_priv::skbcnt variable is used to identify CAN skbs in the RX path analogue to the skb->hash. As the skb hash is not filled in CAN skbs move the private skbcnt value to skb->hash and set skb->sw_hash accordingly. The skb->hash is a value used for RPS to identify skbs. Use it as intended. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-1-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: raw: instantly reject disabled CAN frames

2026-01-15T08:52:04+00:00

For real CAN interfaces the CAN_CTRLMODE_FD and CAN_CTRLMODE_XL control modes indicate whether an interface can handle those CAN FD/XL frames. In the case a CAN XL interface is configured in CANXL-only mode with disabled error-signalling neither CAN CC nor CAN FD frames can be sent. The checks are now performed on CAN_RAW sockets to give an instant feedback to the user when writing unsupported CAN frames to the interface or when the CAN interface is in read-only mode. Fixes: 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") Cc: Marc Kleine-Budde Cc: Arnd Bergmann Cc: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260109144135.8495-4-socketcan@hartkopp.net [mkl: fix dev reference leak] Link: https://lore.kernel.org/all/0636c732-2e71-4633-8005-dfa85e1da445@hartkopp.net Signed-off-by: Marc Kleine-Budde

Revert "can: raw: instantly reject unsupported CAN frames"

2026-01-15T08:52:04+00:00

This reverts commit 1a620a723853a0f49703c317d52dc6b9602cbaa8 and its follow-up fixes for the introduced dependency issues. commit 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") commit cb2dc6d2869a ("can: Kconfig: select CAN driver infrastructure by default") commit 6abd4577bccc ("can: fix build dependency") commit 5a5aff6338c0 ("can: fix build dependency") The entire problem was caused by the requirement that a new network layer feature needed to know about the protocol capabilities of the CAN devices. Instead of accessing CAN device internal data structures which caused the dependency problems a better approach has been developed which makes use of CAN specific ml_priv data which is accessible from both sides. Cc: Marc Kleine-Budde Cc: Arnd Bergmann Cc: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260109144135.8495-2-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: raw: instantly reject unsupported CAN frames

2025-11-26T10:20:44+00:00

net: Convert proto_ops bind() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski

can: annotate mtu accesses with READ_ONCE()

2025-09-23T08:04:58+00:00

As hinted in commit 501a90c94510 ("inet: protect against too small mtu values."), net_device->mtu is vulnerable to race conditions if it is written and read without holding the RTNL. At the moment, all the writes are done while the interface is down, either in the devices' probe() function or in can_changelink(). So there are no such issues yet. But upcoming changes will allow to modify the MTU while the CAN XL devices are up. In preparation to the introduction of CAN XL, annotate all the net_device->mtu accesses which are not yet guarded by the RTNL with a READ_ONCE(). Note that all the write accesses are already either guarded by the RTNL or are already annotated and thus need no changes. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-can-fix-mtu-v3-1-581bde113f52@kernel.org Signed-off-by: Marc Kleine-Budde