kernel/linux.git, branch v3.18.125

Linux 3.18.125

2018-11-10T15:39:23+00:00

sched/fair: Fix throttle_list starvation with low CFS quota

2018-11-10T15:39:23+00:00

commit baa9be4ffb55876923dc9716abc0a448e510ba30 upstream. With a very low cpu.cfs_quota_us setting, such as the minimum of 1000, distribute_cfs_runtime may not empty the throttled_list before it runs out of runtime to distribute. In that case, due to the change from c06f04c7048 to put throttled entries at the head of the list, later entries on the list will starve. Essentially, the same X processes will get pulled off the list, given CPU time and then, when expired, get put back on the head of the list where distribute_cfs_runtime will give runtime to the same set of processes leaving the rest. Fix the issue by setting a bit in struct cfs_bandwidth when distribute_cfs_runtime is running, so that the code in throttle_cfs_rq can decide to put the throttled entry on the tail or the head of the list. The bit is set/cleared by the callers of distribute_cfs_runtime while they hold cfs_bandwidth->lock. This is easy to reproduce with a handful of CPU consumers. I use 'crash' on the live system. In some cases you can simply look at the throttled list and see the later entries are not changing: crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3 1 ffff90b56cb2d200 -976050 2 ffff90b56cb2cc00 -484925 3 ffff90b56cb2bc00 -658814 4 ffff90b56cb2ba00 -275365 5 ffff90b166a45600 -135138 6 ffff90b56cb2da00 -282505 7 ffff90b56cb2e000 -148065 8 ffff90b56cb2fa00 -872591 9 ffff90b56cb2c000 -84687 10 ffff90b56cb2f000 -87237 11 ffff90b166a40a00 -164582 crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3 1 ffff90b56cb2d200 -994147 2 ffff90b56cb2cc00 -306051 3 ffff90b56cb2bc00 -961321 4 ffff90b56cb2ba00 -24490 5 ffff90b166a45600 -135138 6 ffff90b56cb2da00 -282505 7 ffff90b56cb2e000 -148065 8 ffff90b56cb2fa00 -872591 9 ffff90b56cb2c000 -84687 10 ffff90b56cb2f000 -87237 11 ffff90b166a40a00 -164582 Sometimes it is easier to see by finding a process getting starved and looking at the sched_info: crash> task ffff8eb765994500 sched_info PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest" sched_info = { pcount = 8, run_delay = 697094208, last_arrival = 240260125039, last_queued = 240260327513 }, crash> task ffff8eb765994500 sched_info PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest" sched_info = { pcount = 8, run_delay = 697094208, last_arrival = 240260125039, last_queued = 240260327513 }, Signed-off-by: Phil Auld Reviewed-by: Ben Segall Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org Fixes: c06f04c70489 ("sched: Fix potential near-infinite distribute_cfs_runtime() loop") Link: http://lkml.kernel.org/r/20181008143639.GA4019@pauld.bos.csb Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

USB: fix the usbfs flag sanitization for control transfers

2018-11-10T15:39:23+00:00

commit 665c365a77fbfeabe52694aedf3446d5f2f1ce42 upstream. Commit 7a68d9fb8510 ("USB: usbdevfs: sanitize flags more") checks the transfer flags for URBs submitted from userspace via usbfs. However, the check for whether the USBDEVFS_URB_SHORT_NOT_OK flag should be allowed for a control transfer was added in the wrong place, before the code has properly determined the direction of the control transfer. (Control transfers are special because for them, the direction is set by the bRequestType byte of the Setup packet rather than direction bit of the endpoint address.) This patch moves code which sets up the allow_short flag for control transfers down after is_in has been set to the correct value. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+24a30223a4b609bb802e@syzkaller.appspotmail.com Fixes: 7a68d9fb8510 ("USB: usbdevfs: sanitize flags more") CC: Oliver Neukum CC: Signed-off-by: Greg Kroah-Hartman

cdc-acm: correct counting of UART states in serial state notification

2018-11-10T15:39:23+00:00

commit f976d0e5747ca65ccd0fb2a4118b193d70aa1836 upstream. The usb standard ("Universal Serial Bus Class Definitions for Communication Devices") distiguishes between "consistent signals" (DSR, DCD), and "irregular signals" (break, ring, parity error, framing error, overrun). The bits of "irregular signals" are set, if this error/event occurred on the device side and are immeadeatly unset, if the serial state notification was sent. Like other drivers of real serial ports do, just the occurence of those events should be counted in serial_icounter_struct (but no 1->0 transitions). Signed-off-by: Tobias Herzog Acked-by: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman

cachefiles: fix the race between cachefiles_bury_object() and rmdir(2)

2018-11-10T15:39:23+00:00

commit 169b803397499be85bdd1e3d07d6f5e3d4bd669e upstream. the victim might've been rmdir'ed just before the lock_rename(); unlike the normal callers, we do not look the source up after the parents are locked - we know it beforehand and just recheck that it's still the child of what used to be its parent. Unfortunately, the check is too weak - we don't spot a dead directory since its ->d_parent is unchanged, dentry is positive, etc. So we sail all the way to ->rename(), with hosting filesystems _not_ expecting to be asked renaming an rmdir'ed subdirectory. The fix is easy, fortunately - the lock on parent is sufficient for making IS_DEADDIR() on child safe. Cc: stable@vger.kernel.org Fixes: 9ae326a69004 (CacheFiles: A cache that backs onto a mounted filesystem) Signed-off-by: Al Viro Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

net: sched: gred: pass the right attribute to gred_change_table_def()

2018-11-10T15:39:23+00:00

[ Upstream commit 38b4f18d56372e1e21771ab7b0357b853330186c ] gred_change_table_def() takes a pointer to TCA_GRED_DPS attribute, and expects it will be able to interpret its contents as struct tc_gred_sopt. Pass the correct gred attribute, instead of TCA_OPTIONS. This bug meant the table definition could never be changed after Qdisc was initialized (unless whatever TCA_OPTIONS contained both passed netlink validation and was a valid struct tc_gred_sopt...). Old behaviour: $ ip link add type dummy $ tc qdisc replace dev dummy0 parent root handle 7: \ gred setup vqs 4 default 0 $ tc qdisc replace dev dummy0 parent root handle 7: \ gred setup vqs 4 default 0 RTNETLINK answers: Invalid argument Now: $ ip link add type dummy $ tc qdisc replace dev dummy0 parent root handle 7: \ gred setup vqs 4 default 0 $ tc qdisc replace dev dummy0 parent root handle 7: \ gred setup vqs 4 default 0 $ tc qdisc replace dev dummy0 parent root handle 7: \ gred setup vqs 4 default 0 Fixes: f62d6b936df5 ("[PKT_SCHED]: GRED: Use central VQ change procedure") Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

rtnetlink: Disallow FDB configuration for non-Ethernet device

2018-11-10T15:39:22+00:00

[ Upstream commit da71577545a52be3e0e9225a946e5fd79cfab015 ] When an FDB entry is configured, the address is validated to have the length of an Ethernet address, but the device for which the address is configured can be of any type. The above can result in the use of uninitialized memory when the address is later compared against existing addresses since 'dev->addr_len' is used and it may be greater than ETH_ALEN, as with ip6tnl devices. Fix this by making sure that FDB entries are only configured for Ethernet devices. BUG: KMSAN: uninit-value in memcmp+0x11d/0x180 lib/string.c:863 CPU: 1 PID: 4318 Comm: syz-executor998 Not tainted 4.19.0-rc3+ #49 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x14b/0x190 lib/dump_stack.c:113 kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:956 __msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:645 memcmp+0x11d/0x180 lib/string.c:863 dev_uc_add_excl+0x165/0x7b0 net/core/dev_addr_lists.c:464 ndo_dflt_fdb_add net/core/rtnetlink.c:3463 [inline] rtnl_fdb_add+0x1081/0x1270 net/core/rtnetlink.c:3558 rtnetlink_rcv_msg+0xa0b/0x1530 net/core/rtnetlink.c:4715 netlink_rcv_skb+0x36e/0x5f0 net/netlink/af_netlink.c:2454 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4733 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1638/0x1720 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x1205/0x1290 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x440ee9 Code: e8 cc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fff6a93b518 EFLAGS: 00000213 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440ee9 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000213 R12: 000000000000b4b0 R13: 0000000000401ec0 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:181 kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:100 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2718 [inline] __kmalloc_node_track_caller+0x9e7/0x1160 mm/slub.c:4351 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2f5/0x9e0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:996 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline] netlink_sendmsg+0xb49/0x1290 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe70/0x1290 net/socket.c:2114 __sys_sendmsg net/socket.c:2152 [inline] __do_sys_sendmsg net/socket.c:2161 [inline] __se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159 do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 v2: * Make error message more specific (David) Fixes: 090096bf3db1 ("net: generic fdb support for drivers without ndo_fdb_") Signed-off-by: Ido Schimmel Reported-and-tested-by: syzbot+3a288d5f5530b901310e@syzkaller.appspotmail.com Reported-and-tested-by: syzbot+d53ab4e92a1db04110ff@syzkaller.appspotmail.com Cc: Vlad Yasevich Cc: David Ahern Reviewed-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: drop skb on failure in ip_check_defrag()

2018-11-10T15:39:22+00:00

[ Upstream commit 7de414a9dd91426318df7b63da024b2b07e53df5 ] Most callers of pskb_trim_rcsum() simply drop the skb when it fails, however, ip_check_defrag() still continues to pass the skb up to stack. This is suspicious. In ip_check_defrag(), after we learn the skb is an IP fragment, passing the skb to callers makes no sense, because callers expect fragments are defrag'ed on success. So, dropping the skb when we can't defrag it is reasonable. Note, prior to commit 88078d98d1bb, this is not a big problem as checksum will be fixed up anyway. After it, the checksum is not correct on failure. Found this during code review. Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends") Cc: Eric Dumazet Signed-off-by: Cong Wang Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix race on sctp_id2asoc

2018-11-10T15:39:22+00:00

[ Upstream commit b336decab22158937975293aea79396525f92bb3 ] syzbot reported an use-after-free involving sctp_id2asoc. Dmitry Vyukov helped to root cause it and it is because of reading the asoc after it was freed: CPU 1 CPU 2 (working on socket 1) (working on socket 2) sctp_association_destroy sctp_id2asoc spin lock grab the asoc from idr spin unlock spin lock remove asoc from idr spin unlock free(asoc) if asoc->base.sk != sk ... [*] This can only be hit if trying to fetch asocs from different sockets. As we have a single IDR for all asocs, in all SCTP sockets, their id is unique on the system. An application can try to send stuff on an id that matches on another socket, and the if in [*] will protect from such usage. But it didn't consider that as that asoc may belong to another socket, it may be freed in parallel (read: under another socket lock). We fix it by moving the checks in [*] into the protected region. This fixes it because the asoc cannot be freed while the lock is held. Reported-by: syzbot+c7dd55d7aec49d48e49a@syzkaller.appspotmail.com Acked-by: Dmitry Vyukov Signed-off-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

r8169: fix NAPI handling under high load

2018-11-10T15:39:22+00:00

[ Upstream commit 6b839b6cf9eada30b086effb51e5d6076bafc761 ] rtl_rx() and rtl_tx() are called only if the respective bits are set in the interrupt status register. Under high load NAPI may not be able to process all data (work_done == budget) and it will schedule subsequent calls to the poll callback. rtl_ack_events() however resets the bits in the interrupt status register, therefore subsequent calls to rtl8169_poll() won't call rtl_rx() and rtl_tx() - chip interrupts are still disabled. Fix this by calling rtl_rx() and rtl_tx() independent of the bits set in the interrupt status register. Both functions will detect if there's nothing to do for them. Fixes: da78dbff2e05 ("r8169: remove work from irq handler.") Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman