From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Qian Cai <cai@lca.pw>, "David S . Miller" <davem@davemloft.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 33/90] skbuff: fix a data race in skb_queue_len()
Date: Thu, 17 Sep 2020 22:13:58 -0400 [thread overview]
Message-ID: <20200918021455.2067301-33-sashal@kernel.org> (raw)
In-Reply-To: <20200918021455.2067301-1-sashal@kernel.org>
From: Qian Cai <cai@lca.pw>
[ Upstream commit 86b18aaa2b5b5bb48e609cd591b3d2d0fdbe0442 ]
sk_buff.qlen can be accessed concurrently as noticed by KCSAN,
BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_dgram_sendmsg
read to 0xffff8a1b1d8a81c0 of 4 bytes by task 5371 on cpu 96:
unix_dgram_sendmsg+0x9a9/0xb70 include/linux/skbuff.h:1821
net/unix/af_unix.c:1761
____sys_sendmsg+0x33e/0x370
___sys_sendmsg+0xa6/0xf0
__sys_sendmsg+0x69/0xf0
__x64_sys_sendmsg+0x51/0x70
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
write to 0xffff8a1b1d8a81c0 of 4 bytes by task 1 on cpu 99:
__skb_try_recv_from_queue+0x327/0x410 include/linux/skbuff.h:2029
__skb_try_recv_datagram+0xbe/0x220
unix_dgram_recvmsg+0xee/0x850
____sys_recvmsg+0x1fb/0x210
___sys_recvmsg+0xa2/0xf0
__sys_recvmsg+0x66/0xf0
__x64_sys_recvmsg+0x51/0x70
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Since only the read is operating as lockless, it could introduce a logic
bug in unix_recvq_full() due to the load tearing. Fix it by adding
a lockless variant of skb_queue_len() and unix_recvq_full() where
READ_ONCE() is on the read while WRITE_ONCE() is on the write similar to
the commit d7d16a89350a ("net: add skb_queue_empty_lockless()").
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/skbuff.h | 14 +++++++++++++-
net/unix/af_unix.c | 11 +++++++++--
2 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index e37112ac332f7..0380fd29824e0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1549,6 +1549,18 @@ static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
return list_->qlen;
}
+/**
+ * skb_queue_len_lockless - get queue length
+ * @list_: list to measure
+ *
+ * Return the length of an &sk_buff queue.
+ * This variant can be used in lockless contexts.
+ */
+static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
+{
+ return READ_ONCE(list_->qlen);
+}
+
/**
* __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
* @list: queue to initialize
@@ -1752,7 +1764,7 @@ static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
{
struct sk_buff *next, *prev;
- list->qlen--;
+ WRITE_ONCE(list->qlen, list->qlen - 1);
next = skb->next;
prev = skb->prev;
skb->next = skb->prev = NULL;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 32ae82a5596d9..bcd6ed6e7e25c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -191,11 +191,17 @@ static inline int unix_may_send(struct sock *sk, struct sock *osk)
return unix_peer(osk) == NULL || unix_our_peer(sk, osk);
}
-static inline int unix_recvq_full(struct sock const *sk)
+static inline int unix_recvq_full(const struct sock *sk)
{
return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
}
+static inline int unix_recvq_full_lockless(const struct sock *sk)
+{
+ return skb_queue_len_lockless(&sk->sk_receive_queue) >
+ READ_ONCE(sk->sk_max_ack_backlog);
+}
+
struct sock *unix_peer_get(struct sock *s)
{
struct sock *peer;
@@ -1793,7 +1799,8 @@ restart_locked:
* - unix_peer(sk) == sk by time of get but disconnected before lock
*/
if (other != sk &&
- unlikely(unix_peer(other) != sk && unix_recvq_full(other))) {
+ unlikely(unix_peer(other) != sk &&
+ unix_recvq_full_lockless(other))) {
if (timeo) {
timeo = unix_wait_for_peer(other, timeo);
--
2.25.1
next prev parent reply other threads:[~2020-09-18 2:15 UTC|newest]
Thread overview: 95+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-18 2:13 [PATCH AUTOSEL 4.9 01/90] scsi: aacraid: fix illegal IO beyond last LBA Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 02/90] m68k: q40: Fix info-leak in rtc_ioctl Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 03/90] gma/gma500: fix a memory disclosure bug due to uninitialized bytes Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 04/90] ASoC: kirkwood: fix IRQ error handling Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 05/90] ata: sata_mv, avoid trigerrable BUG_ON Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 06/90] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 07/90] clk/ti/adpll: allocate room for terminating null Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 08/90] mtd: cfi_cmdset_0002: don't free cfi->cfiq in error path of cfi_amdstd_setup() Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 09/90] mfd: mfd-core: Protect against NULL call-back function pointer Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 10/90] tracing: Adding NULL checks for trace_array descriptor pointer Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 11/90] bcache: fix a lost wake-up problem caused by mca_cannibalize_lock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 12/90] RDMA/i40iw: Fix potential use after free Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 13/90] xfs: fix attr leaf header freemap.size underflow Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 14/90] RDMA/iw_cgxb4: Fix an error handling path in 'c4iw_connect()' Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 15/90] debugfs: Fix !DEBUG_FS debugfs_create_automount Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 16/90] CIFS: Properly process SMB3 lease breaks Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 17/90] kernel/sys.c: avoid copying possible padding bytes in copy_to_user Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 18/90] neigh_stat_seq_next() should increase position index Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 19/90] rt_cpu_seq_next " Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 20/90] seqlock: Require WRITE_ONCE surrounding raw_seqcount_barrier Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 21/90] media: ti-vpe: cal: Restrict DMA to avoid memory corruption Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 22/90] ACPI: EC: Reference count query handlers under lock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 23/90] efi/arm: Defer probe of PCIe backed efifb on DT systems Sasha Levin
2020-09-18 6:25 ` Ard Biesheuvel
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 24/90] dmaengine: zynqmp_dma: fix burst length configuration Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 25/90] tracing: Set kernel_stack's caller size properly Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 26/90] ext4: make dioread_nolock the default Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 27/90] ar5523: Add USB ID of SMCWUSBT-G2 wireless adapter Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 28/90] Bluetooth: Fix refcount use-after-free issue Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 29/90] mm: pagewalk: fix termination condition in walk_pte_range() Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 30/90] Bluetooth: prefetch channel before killing sock Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 31/90] KVM: fix overflow of zero page refcount with ksm running Sasha Levin
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 32/90] ALSA: hda: Clear RIRB status before reading WP Sasha Levin
2020-09-18 2:13 ` Sasha Levin [this message]
2020-09-18 2:13 ` [PATCH AUTOSEL 4.9 34/90] audit: CONFIG_CHANGE don't log internal bookkeeping as an event Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 35/90] selinux: sel_avc_get_stat_idx should increase position index Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 36/90] scsi: lpfc: Fix RQ buffer leakage when no IOCBs available Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 37/90] scsi: lpfc: Fix coverity errors in fmdi attribute handling Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 38/90] drm/omap: fix possible object reference leak Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 39/90] RDMA/rxe: Fix configuration of atomic queue pair attributes Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 40/90] KVM: x86: fix incorrect comparison in trace event Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 41/90] x86/pkeys: Add check for pkey "overflow" Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 42/90] bpf: Remove recursion prevention from rcu free callback Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 43/90] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 44/90] media: go7007: Fix URB type for interrupt handling Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 45/90] Bluetooth: guard against controllers sending zero'd events Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 46/90] timekeeping: Prevent 32bit truncation in scale64_check_overflow() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 47/90] drm/amdgpu: increase atombios cmd timeout Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 48/90] Bluetooth: L2CAP: handle l2cap config request during open state Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 49/90] media: tda10071: fix unsigned sign extension overflow Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 50/90] xfs: don't ever return a stale pointer from __xfs_dir3_free_read Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 51/90] tpm: ibmvtpm: Wait for buffer to be set before proceeding Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 52/90] tracing: Use address-of operator on section symbols Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 53/90] serial: 8250_port: Don't service RX FIFO if throttled Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 54/90] serial: 8250_omap: Fix sleeping function called from invalid context during probe Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 55/90] serial: 8250: 8250_omap: Terminate DMA before pushing data on RX timeout Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 56/90] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 57/90] tools: gpio-hammer: Avoid potential overflow in main Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 58/90] SUNRPC: Fix a potential buffer overflow in 'svc_print_xprts()' Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 59/90] svcrdma: Fix leak of transport addresses Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 60/90] ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 61/90] ALSA: usb-audio: Fix case when USB MIDI interface has more than one extra endpoint descriptor Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 62/90] mm/filemap.c: clear page error before actual read Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 63/90] mm/mmap.c: initialize align_offset explicitly for vm_unmapped_area Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 64/90] serial: uartps: Wait for tx_empty in console setup Sasha Levin
2020-09-28 20:11 ` Naresh Kamboju
2020-09-28 20:13 ` Naresh Kamboju
2020-09-29 6:59 ` Greg Kroah-Hartman
2020-09-29 17:39 ` Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 65/90] KVM: Remove CREATE_IRQCHIP/SET_PIT2 race Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 66/90] bdev: Reduce time holding bd_mutex in sync in blkdev_close() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 67/90] drivers: char: tlclk.c: Avoid data race between init and interrupt handler Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 68/90] dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 69/90] atm: fix a memory leak of vcc->user_back Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 70/90] phy: samsung: s5pv210-usb2: Add delay after reset Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 71/90] Bluetooth: Handle Inquiry Cancel error after Inquiry Complete Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 72/90] USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe() Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 73/90] tty: serial: samsung: Correct clock selection logic Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 74/90] ALSA: hda: Fix potential race in unsol event handler Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 75/90] fuse: don't check refcount after stealing page Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 76/90] USB: EHCI: ehci-mv: fix less than zero comparison of an unsigned int Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 77/90] e1000: Do not perform reset in reset_task if we are already down Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 78/90] printk: handle blank console arguments passed in Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 79/90] btrfs: don't force read-only after error in drop snapshot Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 80/90] vfio/pci: fix memory leaks of eventfd ctx Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 81/90] perf util: Fix memory leak of prefix_if_not_in Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 82/90] perf kcore_copy: Fix module map when there are no modules loaded Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 83/90] mtd: rawnand: omap_elm: Fix runtime PM imbalance on error Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 84/90] ceph: fix potential race in ceph_check_caps Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 85/90] mtd: parser: cmdline: Support MTD names containing one or more colons Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 86/90] x86/speculation/mds: Mark mds_user_clear_cpu_buffers() __always_inline Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 87/90] vfio/pci: Clear error and request eventfd ctx after releasing Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 88/90] cifs: Fix double add page to memcg when cifs_readpages Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 89/90] selftests/x86/syscall_nt: Clear weird flags after each test Sasha Levin
2020-09-18 2:14 ` [PATCH AUTOSEL 4.9 90/90] vfio/pci: fix racy on error and request eventfd ctx Sasha Levin
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