kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-20 19:23:40 +00:00
Code Issues Releases Packages Activity
No description
1,079,261 commits 117 branches 5,799 tags 5.6 GiB
  • C 96.9%
  • Assembly 0.9%
  • Rust 0.6%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Weiming Shi 9918698cf3 net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink() 
commit d00c953a8f upstream.

rmnet_dellink() removes the endpoint from the hash table with
hlist_del_init_rcu() and then immediately frees it with kfree(). However,
RCU readers on the receive path (rmnet_rx_handler ->
__rmnet_map_ingress_handler) may still hold a reference to the endpoint and
dereference ep->egress_dev after the memory has been freed. The endpoint is
a kmalloc-32 object, and the stale read at offset 8 corresponds to the
egress_dev pointer.

  BUG: unable to handle page fault for address: ffffffffde942eef
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 UID: 0 PID: 137 Comm: poc_write Not tainted 7.0.0+ #4 PREEMPTLAZY
  RIP: 0010:rmnet_vnd_rx_fixup (rmnet_vnd.c:27)
  Call Trace:
   <TASK>
   __rmnet_map_ingress_handler (rmnet_handlers.c:48 rmnet_handlers.c:101)
   rmnet_rx_handler (rmnet_handlers.c:129 rmnet_handlers.c:235)
   __netif_receive_skb_core.constprop.0 (net/core/dev.c:6096)
   __netif_receive_skb_one_core (net/core/dev.c:6208)
   netif_receive_skb (net/core/dev.c:6467)
   tun_get_user (drivers/net/tun.c:1955)
   tun_chr_write_iter (drivers/net/tun.c:2003)
   vfs_write (fs/read_write.c:688)
   ksys_write (fs/read_write.c:740)
   </TASK>

Add an rcu_head field to struct rmnet_endpoint and replace kfree() with
kfree_rcu() so the endpoint memory remains valid through the RCU grace
period. Also remove the rmnet_vnd_dellink() call and inline only the
nr_rmnet_devs decrement, since rmnet_vnd_dellink() would set
ep->egress_dev to NULL during the grace period, creating a data race
with lockless readers.

Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Link: https://patch.msgid.link/20260514122511.3083479-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2026-07-04 13:39:37 +02:00
arch
block
certs
crypto
Documentation
drivers
fs
include
init
io_uring
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

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.