leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
mainlining shenanigans
726,129 Commits 2 Branches 0 Tags 5.1 GiB
C 97.7%
Assembly 1.1%
Shell 0.4%
Makefile 0.3%
Python 0.2%
Other 0.1%
6dd1ec6c7a
Go to file
Yonghong Song 6dd1ec6c7a bpf: fix kernel page fault in lpm map trie_get_next_key 
Commit b471f2f1de ("bpf: implement MAP_GET_NEXT_KEY command
for LPM_TRIE map") introduces a bug likes below:

    if (!rcu_dereference(trie->root))
        return -ENOENT;
    if (!key || key->prefixlen > trie->max_prefixlen) {
        root = &trie->root;
        goto find_leftmost;
    }
    ......
  find_leftmost:
    for (node = rcu_dereference(*root); node;) {

In the code after label find_leftmost, it is assumed
that *root should not be NULL, but it is not true as
it is possbile trie->root is changed to NULL by an
asynchronous delete operation.

The issue is reported by syzbot and Eric Dumazet with the
below error log:
  ......
  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] SMP KASAN
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Modules linked in:
  CPU: 1 PID: 8033 Comm: syz-executor3 Not tainted 4.15.0-rc8+ #4
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:trie_get_next_key+0x3c2/0xf10 kernel/bpf/lpm_trie.c:682
  ......

This patch fixed the issue by use local rcu_dereferenced
pointer instead of *(&trie->root) later on.

Fixes: b471f2f1de ("bpf: implement MAP_GET_NEXT_KEY command or LPM_TRIE map")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-01-26 17:06:22 -08:00
arch bpf, arm: remove obsolete exception handling from div/mod 2018-01-26 16:42:07 -08:00
block block: drain queue before waiting for q_usage_counter becoming zero 2018-01-05 09:09:48 -07:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-01-12 09:47:58 -08:00
Documentation bpf, doc: Correct one wrong value in "Register value tracking" 2018-01-24 16:43:11 +01:00
drivers net: aquantia: make symbol hw_atl_boards static 2018-01-23 10:59:42 -05:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-19 22:59:33 -05:00
include bpf: make unknown opcode handling more robust 2018-01-26 16:42:05 -08:00
init Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-12 10:23:59 -08:00
ipc Rename superblock flags (MS_xyz -> SB_xyz) 2017-11-27 13:05:09 -08:00
kernel bpf: fix kernel page fault in lpm map trie_get_next_key 2018-01-26 17:06:22 -08:00
lib bpf: add further test cases around div/mod and others 2018-01-26 16:42:07 -08:00
mm mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages 2018-01-19 10:09:40 -08:00
net bpf: fix subprog verifier bypass by div/mod by 0 exception 2018-01-26 16:42:05 -08:00
samples samples/bpf: Partially fixes the bpf.o build 2018-01-26 23:57:10 +01:00
scripts scripts/gdb/linux/tasks.py: fix get_thread_info 2018-01-19 10:09:41 -08:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-01-17 00:10:42 -05:00
sound ALSA: seq: Make ioctls race-free 2018-01-11 14:37:51 +01:00
tools bpf: add further test cases around div/mod and others 2018-01-26 16:42:07 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM/ARM Fixes for v4.15, Round 2 2017-12-18 12:57:43 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap mailmap: update Mark Yao's email address 2018-01-04 16:45:09 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS wireless-drivers-next patches for 4.16 2018-01-19 10:26:53 -05:00
Makefile Linux 4.15-rc8 2018-01-14 15:32:30 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README 

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.