kernel/linux.git/drivers/connector/connector.c, branch linux-4.16.y

drivers, connector: convert cn_callback_entry.refcnt from atomic_t to refcount_t

2017-10-22T01:22:39+00:00

atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable cn_callback_entry.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook Reviewed-by: David Windsor Reviewed-by: Hans Liljestrand Signed-off-by: Elena Reshetova Signed-off-by: David S. Miller

connector: bump skb->users before callback invocation

2016-01-05T02:46:45+00:00

Dmitry reports memleak with syskaller program. Problem is that connector bumps skb usecount but might not invoke callback. So move skb_get to where we invoke the callback. Reported-by: Dmitry Vyukov Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

2015-11-07T01:50:42+00:00

__GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Christoph Lameter Cc: David Rientjes Cc: Vitaly Wool Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cn: verify msg->len before making callback

2014-11-27T03:09:01+00:00

The struct cn_msg len field comes from userspace and needs to be validated. More logical to do so here where the cn_msg pointer is pulled out of the sk_buff than the callback which is passed cn_msg * and might assume no validation is needed. Reported-by: Dan Carpenter Acked-by: Evgeniy Polyakov Signed-off-by: David Fries Signed-off-by: Greg Kroah-Hartman

connector: allow multiple messages to be sent in one packet

2014-05-27T20:56:21+00:00

This increases the amount of bundling to reduce the number of packets sent. For the one wire use there can be multiple struct w1_netlink_cmd in a struct w1_netlink_msg and multiple of those in struct cn_msg, and with this change multiple of those in a struct nlmsghdr, and at each level the len identifies there being multiple of the next. Signed-off-by: David Fries Acked-by: Evgeniy Polyakov Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2014-04-03T03:53:45+00:00

Pull networking updates from David Miller: "Here is my initial pull request for the networking subsystem during this merge window: 1) Support for ESN in AH (RFC 4302) from Fan Du. 2) Add full kernel doc for ethtool command structures, from Ben Hutchings. 3) Add BCM7xxx PHY driver, from Florian Fainelli. 4) Export computed TCP rate information in netlink socket dumps, from Eric Dumazet. 5) Allow IPSEC SA to be dumped partially using a filter, from Nicolas Dichtel. 6) Convert many drivers to pci_enable_msix_range(), from Alexander Gordeev. 7) Record SKB timestamps more efficiently, from Eric Dumazet. 8) Switch to microsecond resolution for TCP round trip times, also from Eric Dumazet. 9) Clean up and fix 6lowpan fragmentation handling by making use of the existing inet_frag api for it's implementation. 10) Add TX grant mapping to xen-netback driver, from Zoltan Kiss. 11) Auto size SKB lengths when composing netlink messages based upon past message sizes used, from Eric Dumazet. 12) qdisc dumps can take a long time, add a cond_resched(), From Eric Dumazet. 13) Sanitize netpoll core and drivers wrt. SKB handling semantics. Get rid of never-used-in-tree netpoll RX handling. From Eric W Biederman. 14) Support inter-address-family and namespace changing in VTI tunnel driver(s). From Steffen Klassert. 15) Add Altera TSE driver, from Vince Bridgers. 16) Optimizing csum_replace2() so that it doesn't adjust the checksum by checksumming the entire header, from Eric Dumazet. 17) Expand BPF internal implementation for faster interpreting, more direct translations into JIT'd code, and much cleaner uses of BPF filtering in non-socket ocntexts. From Daniel Borkmann and Alexei Starovoitov" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1976 commits) netpoll: Use skb_irq_freeable to make zap_completion_queue safe. net: Add a test to see if a skb is freeable in irq context qlcnic: Fix build failure due to undefined reference to `vxlan_get_rx_port' net: ptp: move PTP classifier in its own file net: sxgbe: make "core_ops" static net: sxgbe: fix logical vs bitwise operation net: sxgbe: sxgbe_mdio_register() frees the bus Call efx_set_channels() before efx->type->dimension_resources() xen-netback: disable rogue vif in kthread context net/mlx4: Set proper build dependancy with vxlan be2net: fix build dependency on VxLAN mac802154: make csma/cca parameters per-wpan mac802154: allow only one WPAN to be up at any given time net: filter: minor: fix kdoc in __sk_run_filter netlink: don't compare the nul-termination in nla_strcmp can: c_can: Avoid led toggling for every packet. can: c_can: Simplify TX interrupt cleanup can: c_can: Store dlc private can: c_can: Reduce register access can: c_can: Make the code readable ...

connector: remove duplicated code in cn_call_callback()

2014-03-03T20:39:20+00:00

There were a couple of patches fixing the same bug that results in duplicated err = 0; assignment. The patch removes one of them. Signed-off-by: Alexey Khoroshilov Signed-off-by: David S. Miller

connector: add portid to unicast in addition to broadcasting

2014-02-07T23:40:17+00:00

This allows replying only to the requestor portid while still supporting broadcasting. Pass 0 to portid for the previous behavior. Signed-off-by: David Fries Acked-by: Evgeniy Polyakov Signed-off-by: Greg Kroah-Hartman

connector: use 'size' everywhere in cn_netlink_send()

2013-10-02T20:03:50+00:00

We calculated the size for the netlink message buffer as size. Use size in the memcpy() call as well instead of recalculating it. Signed-off-by: Mathias Krause Signed-off-by: David S. Miller

connector: use nlmsg_len() to check message length

2013-10-02T20:03:50+00:00

The current code tests the length of the whole netlink message to be at least as long to fit a cn_msg. This is wrong as nlmsg_len includes the length of the netlink message header. Use nlmsg_len() instead to fix this "off-by-NLMSG_HDRLEN" size check. Cc: stable@vger.kernel.org # v2.6.14+ Signed-off-by: Mathias Krause Signed-off-by: David S. Miller