mirror of
https://github.com/torvalds/linux.git
synced 2024-10-25 14:40:58 +00:00
A mirror of the official Linux kernel repository just in case
144748eb0c
Incorrect accounting fwd_alloc can result in a warning when the socket
is torn down,
[18455.319240] WARNING: CPU: 0 PID: 24075 at net/core/stream.c:208 sk_stream_kill_queues+0x21f/0x230
[...]
[18455.319543] Call Trace:
[18455.319556] inet_csk_destroy_sock+0xba/0x1f0
[18455.319577] tcp_rcv_state_process+0x1b4e/0x2380
[18455.319593] ? lock_downgrade+0x3a0/0x3a0
[18455.319617] ? tcp_finish_connect+0x1e0/0x1e0
[18455.319631] ? sk_reset_timer+0x15/0x70
[18455.319646] ? tcp_schedule_loss_probe+0x1b2/0x240
[18455.319663] ? lock_release+0xb2/0x3f0
[18455.319676] ? __release_sock+0x8a/0x1b0
[18455.319690] ? lock_downgrade+0x3a0/0x3a0
[18455.319704] ? lock_release+0x3f0/0x3f0
[18455.319717] ? __tcp_close+0x2c6/0x790
[18455.319736] ? tcp_v4_do_rcv+0x168/0x370
[18455.319750] tcp_v4_do_rcv+0x168/0x370
[18455.319767] __release_sock+0xbc/0x1b0
[18455.319785] __tcp_close+0x2ee/0x790
[18455.319805] tcp_close+0x20/0x80
This currently happens because on redirect case we do skb_set_owner_r()
with the original sock. This increments the fwd_alloc memory accounting
on the original sock. Then on redirect we may push this into the queue
of the psock we are redirecting to. When the skb is flushed from the
queue we give the memory back to the original sock. The problem is if
the original sock is destroyed/closed with skbs on another psocks queue
then the original sock will not have a way to reclaim the memory before
being destroyed. Then above warning will be thrown
sockA sockB
sk_psock_strp_read()
sk_psock_verdict_apply()
-- SK_REDIRECT --
sk_psock_skb_redirect()
skb_queue_tail(psock_other->ingress_skb..)
sk_close()
sock_map_unref()
sk_psock_put()
sk_psock_drop()
sk_psock_zap_ingress()
At this point we have torn down our own psock, but have the outstanding
skb in psock_other. Note that SK_PASS doesn't have this problem because
the sk_psock_drop() logic releases the skb, its still associated with
our psock.
To resolve lets only account for sockets on the ingress queue that are
still associated with the current socket. On the redirect case we will
check memory limits per
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.