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Joe Damato 08062af0a5 net: napi: Prevent overflow of napi_defer_hard_irqs
In commit 6f8b12d661 ("net: napi: add hard irqs deferral feature")
napi_defer_irqs was added to net_device and napi_defer_irqs_count was
added to napi_struct, both as type int.

This value never goes below zero, so there is not reason for it to be a
signed int. Change the type for both from int to u32, and add an
overflow check to sysfs to limit the value to S32_MAX.

The limit of S32_MAX was chosen because the practical limit before this
patch was S32_MAX (anything larger was an overflow) and thus there are
no behavioral changes introduced. If the extra bit is needed in the
future, the limit can be raised.

Before this patch:

$ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs'
$ cat /sys/class/net/eth4/napi_defer_hard_irqs
-2147483647

After this patch:

$ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs'
bash: line 0: echo: write error: Numerical result out of range

Similarly, /sys/class/net/XXXXX/tx_queue_len is defined as unsigned:

include/linux/netdevice.h:      unsigned int            tx_queue_len;

And has an overflow check:

dev_change_tx_queue_len(..., unsigned long new_len):

  if (new_len != (unsigned int)new_len)
          return -ERANGE;

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240904153431.307932-1-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-05 18:42:56 -07:00
arch LoongArch: KVM: Invalidate guest steal time address on vCPU reset 2024-08-26 23:11:32 +08:00
block block: Read max write zeroes once for __blkdev_issue_write_zeroes() 2024-08-19 09:48:59 -06:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto crypto: testmgr - generate power-of-2 lengths more often 2024-07-13 11:50:28 +12:00
Documentation net: napi: Prevent overflow of napi_defer_hard_irqs 2024-09-05 18:42:56 -07:00
drivers net: phy: Add driver for Motorcomm yt8821 2.5G ethernet phy 2024-09-05 15:21:12 +02:00
fs nfsd-6.11 fixes: 2024-08-29 06:20:44 +12:00
include net: napi: Prevent overflow of napi_defer_hard_irqs 2024-09-05 18:42:56 -07:00
init Rust fixes for v6.11 2024-08-16 11:24:06 -07:00
io_uring io_uring/kbuf: sanitize peek buffer setup 2024-08-21 07:16:38 -06:00
ipc sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
kernel vfs-6.11-rc6.fixes 2024-08-27 16:57:35 +12:00
lib netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03 11:36:43 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: Fix missing folio invalidation calls during truncation 2024-08-24 16:09:16 +02:00
net net: napi: Prevent overflow of napi_defer_hard_irqs 2024-09-05 18:42:56 -07:00
rust rust: net::phy unified genphy_read_status function for C22 and C45 registers 2024-08-30 10:27:35 +01:00
samples treewide: remove unnecessary <linux/version.h> inclusion 2024-08-12 18:36:44 +09:00
scripts net: drop special comment style 2024-08-23 10:21:02 +01:00
security KEYS: trusted: dcp: fix leak of blob encryption key 2024-08-15 22:01:14 +03:00
sound sound fixes for 6.11-rc6 2024-08-28 06:24:22 +12:00
tools selftests: net: convert comma to semicolon 2024-09-04 16:55:49 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt KVM: x86: Disallow read-only memslots for SEV-ES and SEV-SNP (and TDX) 2024-08-14 12:28:24 -04:00
.clang-format Docs: Move clang-format from process/ to dev-tools/ 2024-06-26 16:36:00 -06:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: add .gcda files 2024-08-09 13:18:46 +01:00
.mailmap mailmap: update entry for Sriram Yagnaraman 2024-08-29 10:53:46 +02:00
.rustfmt.toml
COPYING
CREDITS tracing: Update of MAINTAINERS and CREDITS file 2024-07-18 14:08:42 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS can: rockchip_canfd: add driver for Rockchip CAN-FD controller 2024-09-04 14:41:51 +02:00
Makefile Linux 6.11-rc5 2024-08-25 19:07:11 +12:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.