linux.git, branch v5.4.68

Linux 5.4.68

2020-09-26T16:03:16+00:00

Tested-by: Jon Hunter 
Tested-by: Shuah Khan 
Tested-by: Linux Kernel Functional Testing 
Tested-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/20200925124723.575329814@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

iommu/amd: Use cmpxchg_double() when updating 128-bit IRTE

2020-09-26T16:03:15+00:00

commit e52d58d54a321d4fe9d0ecdabe4f8774449f0d6e upstream.

When using 128-bit interrupt-remapping table entry (IRTE) (a.k.a GA mode),
current driver disables interrupt remapping when it updates the IRTE
so that the upper and lower 64-bit values can be updated safely.

However, this creates a small window, where the interrupt could
arrive and result in IO_PAGE_FAULT (for interrupt) as shown below.

  IOMMU Driver            Device IRQ
  ============            ===========
  irte.RemapEn=0
       ...
   change IRTE            IRQ from device ==> IO_PAGE_FAULT !!
       ...
  irte.RemapEn=1

This scenario has been observed when changing irq affinity on a system
running I/O-intensive workload, in which the destination APIC ID
in the IRTE is updated.

Instead, use cmpxchg_double() to update the 128-bit IRTE at once without
disabling the interrupt remapping. However, this means several features,
which require GA (128-bit IRTE) support will also be affected if cmpxchg16b
is not supported (which is unprecedented for AMD processors w/ IOMMU).

Fixes: 880ac60e2538 ("iommu/amd: Introduce interrupt remapping ops structure")
Reported-by: Sean Osborne 
Signed-off-by: Suravee Suthikulpanit 
Tested-by: Erik Rockstrom 
Reviewed-by: Joao Martins 
Link: https://lore.kernel.org/r/20200903093822.52012-3-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel 
Signed-off-by: Greg Kroah-Hartman

mm: memcg: fix memcg reclaim soft lockup

2020-09-26T16:03:15+00:00

commit e3336cab2579012b1e72b5265adf98e2d6e244ad upstream.

We've met softlockup with "CONFIG_PREEMPT_NONE=y", when the target memcg
doesn't have any reclaimable memory.

It can be easily reproduced as below:

  watchdog: BUG: soft lockup - CPU#0 stuck for 111s![memcg_test:2204]
  CPU: 0 PID: 2204 Comm: memcg_test Not tainted 5.9.0-rc2+ #12
  Call Trace:
    shrink_lruvec+0x49f/0x640
    shrink_node+0x2a6/0x6f0
    do_try_to_free_pages+0xe9/0x3e0
    try_to_free_mem_cgroup_pages+0xef/0x1f0
    try_charge+0x2c1/0x750
    mem_cgroup_charge+0xd7/0x240
    __add_to_page_cache_locked+0x2fd/0x370
    add_to_page_cache_lru+0x4a/0xc0
    pagecache_get_page+0x10b/0x2f0
    filemap_fault+0x661/0xad0
    ext4_filemap_fault+0x2c/0x40
    __do_fault+0x4d/0xf9
    handle_mm_fault+0x1080/0x1790

It only happens on our 1-vcpu instances, because there's no chance for
oom reaper to run to reclaim the to-be-killed process.

Add a cond_resched() at the upper shrink_node_memcgs() to solve this
issue, this will mean that we will get a scheduling point for each memcg
in the reclaimed hierarchy without any dependency on the reclaimable
memory in that memcg thus making it more predictable.

Suggested-by: Michal Hocko 
Signed-off-by: Xunlei Pang 
Signed-off-by: Andrew Morton 
Acked-by: Chris Down 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Link: http://lkml.kernel.org/r/1598495549-67324-1-git-send-email-xlpang@linux.alibaba.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Julius Hemanth Pitti 
Signed-off-by: Greg Kroah-Hartman

net: add __must_check to skb_put_padto()

2020-09-26T16:03:15+00:00

[ Upstream commit 4a009cb04aeca0de60b73f37b102573354214b52 ]

skb_put_padto() and __skb_put_padto() callers
must check return values or risk use-after-free.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: qrtr: check skb_put_padto() return value

2020-09-26T16:03:15+00:00

[ Upstream commit 3ca1a42a52ca4b4f02061683851692ad65fefac8 ]

If skb_put_padto() returns an error, skb has been freed.
Better not touch it anymore, as reported by syzbot [1]

Note to qrtr maintainers : this suggests qrtr_sendmsg()
should adjust sock_alloc_send_skb() second parameter
to account for the potential added alignment to avoid
reallocation.

[1]

BUG: KASAN: use-after-free in __skb_insert include/linux/skbuff.h:1907 [inline]
BUG: KASAN: use-after-free in __skb_queue_before include/linux/skbuff.h:2016 [inline]
BUG: KASAN: use-after-free in __skb_queue_tail include/linux/skbuff.h:2049 [inline]
BUG: KASAN: use-after-free in skb_queue_tail+0x6b/0x120 net/core/skbuff.c:3146
Write of size 8 at addr ffff88804d8ab3c0 by task syz-executor.4/4316

CPU: 1 PID: 4316 Comm: syz-executor.4 Not tainted 5.9.0-rc4-syzkaller #0
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+0x1d6/0x29e lib/dump_stack.c:118
 print_address_description+0x66/0x620 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 __skb_insert include/linux/skbuff.h:1907 [inline]
 __skb_queue_before include/linux/skbuff.h:2016 [inline]
 __skb_queue_tail include/linux/skbuff.h:2049 [inline]
 skb_queue_tail+0x6b/0x120 net/core/skbuff.c:3146
 qrtr_tun_send+0x1a/0x40 net/qrtr/tun.c:23
 qrtr_node_enqueue+0x44f/0xc00 net/qrtr/qrtr.c:364
 qrtr_bcast_enqueue+0xbe/0x140 net/qrtr/qrtr.c:861
 qrtr_sendmsg+0x680/0x9c0 net/qrtr/qrtr.c:960
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 sock_write_iter+0x317/0x470 net/socket.c:998
 call_write_iter include/linux/fs.h:1882 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xa96/0xd10 fs/read_write.c:578
 ksys_write+0x11b/0x220 fs/read_write.c:631
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f84b5b81c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000038b40 RCX: 000000000045d5b9
RDX: 0000000000000055 RSI: 0000000020001240 RDI: 0000000000000003
RBP: 00007f84b5b81ca0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000f
R13: 00007ffcbbf86daf R14: 00007f84b5b829c0 R15: 000000000118cf4c

Allocated by task 4316:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
 slab_post_alloc_hook+0x3e/0x290 mm/slab.h:518
 slab_alloc mm/slab.c:3312 [inline]
 kmem_cache_alloc+0x1c1/0x2d0 mm/slab.c:3482
 skb_clone+0x1b2/0x370 net/core/skbuff.c:1449
 qrtr_bcast_enqueue+0x6d/0x140 net/qrtr/qrtr.c:857
 qrtr_sendmsg+0x680/0x9c0 net/qrtr/qrtr.c:960
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 sock_write_iter+0x317/0x470 net/socket.c:998
 call_write_iter include/linux/fs.h:1882 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xa96/0xd10 fs/read_write.c:578
 ksys_write+0x11b/0x220 fs/read_write.c:631
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 4316:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xdd/0x110 mm/kasan/common.c:422
 __cache_free mm/slab.c:3418 [inline]
 kmem_cache_free+0x82/0xf0 mm/slab.c:3693
 __skb_pad+0x3f5/0x5a0 net/core/skbuff.c:1823
 __skb_put_padto include/linux/skbuff.h:3233 [inline]
 skb_put_padto include/linux/skbuff.h:3252 [inline]
 qrtr_node_enqueue+0x62f/0xc00 net/qrtr/qrtr.c:360
 qrtr_bcast_enqueue+0xbe/0x140 net/qrtr/qrtr.c:861
 qrtr_sendmsg+0x680/0x9c0 net/qrtr/qrtr.c:960
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 sock_write_iter+0x317/0x470 net/socket.c:998
 call_write_iter include/linux/fs.h:1882 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0xa96/0xd10 fs/read_write.c:578
 ksys_write+0x11b/0x220 fs/read_write.c:631
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88804d8ab3c0
 which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 0 bytes inside of
 224-byte region [ffff88804d8ab3c0, ffff88804d8ab4a0)
The buggy address belongs to the page:
page:00000000ea8cccfb refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804d8abb40 pfn:0x4d8ab
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002237ec8 ffffea00029b3388 ffff88821bb66800
raw: ffff88804d8abb40 ffff88804d8ab000 000000010000000b 0000000000000000
page dumped because: kasan: bad access detected

Fixes: ce57785bf91b ("net: qrtr: fix len of skb_put_padto in qrtr_node_enqueue")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Cc: Carl Huang 
Cc: Wen Gong 
Cc: Bjorn Andersson 
Cc: Manivannan Sadhasivam 
Acked-by: Manivannan Sadhasivam 
Reviewed-by: Bjorn Andersson 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: phy: Do not warn in phy_stop() on PHY_DOWN

2020-09-26T16:03:15+00:00

[ Upstream commit 5116a8ade333b6c2e180782139c9c516a437b21c ]

When phy_is_started() was added to catch incorrect PHY states,
phy_stop() would not be qualified against PHY_DOWN. It is possible to
reach that state when the PHY driver has been unbound and the network
device is then brought down.

Fixes: 2b3e88ea6528 ("net: phy: improve phy state checking")
Signed-off-by: Florian Fainelli 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: phy: Avoid NPD upon phy_detach() when driver is unbound

2020-09-26T16:03:15+00:00

[ Upstream commit c2b727df7caa33876e7066bde090f40001b6d643 ]

If we have unbound the PHY driver prior to calling phy_detach() (often
via phy_disconnect()) then we can cause a NULL pointer de-reference
accessing the driver owner member. The steps to reproduce are:

echo unimac-mdio-0:01 > /sys/class/net/eth0/phydev/driver/unbind
ip link set eth0 down

Fixes: cafe8df8b9bc ("net: phy: Fix lack of reference count on PHY driver")
Signed-off-by: Florian Fainelli 
Reviewed-by: Andrew Lunn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: lantiq: Disable IRQs only if NAPI gets scheduled

2020-09-26T16:03:15+00:00

[ Upstream commit 9423361da52356cb68642db5b2729b6b85aad330 ]

The napi_schedule() call will only schedule the NAPI if it is not
already running. To make sure that we do not deactivate interrupts
without scheduling NAPI only deactivate the interrupts in case NAPI also
gets scheduled.

Signed-off-by: Hauke Mehrtens 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: lantiq: Use napi_complete_done()

2020-09-26T16:03:15+00:00

[ Upstream commit c582a7fea9dad4d309437d1a7e22e6d2cb380e2e ]

Use napi_complete_done() and activate the interrupts when this function
returns true. This way the generic NAPI code can take care of activating
the interrupts.

Signed-off-by: Hauke Mehrtens 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: lantiq: use netif_tx_napi_add() for TX NAPI

2020-09-26T16:03:14+00:00

[ Upstream commit 74c7b80e222b58d3cea731d31e2a31a77fea8345 ]

netif_tx_napi_add() should be used for NAPI in the TX direction instead
of the netif_napi_add() function.

Signed-off-by: Hauke Mehrtens 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman