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Paolo Abeni 4d42d54a7d net/sched: act_pedit: sanitize shift argument before usage
syzbot was able to trigger an Out-of-Bound on the pedit action:

UBSAN: shift-out-of-bounds in net/sched/act_pedit.c:238:43
shift exponent 1400735974 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 3606 Comm: syz-executor151 Not tainted 5.18.0-rc5-syzkaller-00165-g810c2f0a3f86 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
 tcf_pedit_init.cold+0x1a/0x1f net/sched/act_pedit.c:238
 tcf_action_init_1+0x414/0x690 net/sched/act_api.c:1367
 tcf_action_init+0x530/0x8d0 net/sched/act_api.c:1432
 tcf_action_add+0xf9/0x480 net/sched/act_api.c:1956
 tc_ctl_action+0x346/0x470 net/sched/act_api.c:2015
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5993
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe36e9e1b59
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef796fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe36e9e1b59
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00007fe36e9a5d00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe36e9a5d90
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

The 'shift' field is not validated, and any value above 31 will
trigger out-of-bounds. The issue predates the git history, but
syzbot was able to trigger it only after the commit mentioned in
the fixes tag, and this change only applies on top of such commit.

Address the issue bounding the 'shift' value to the maximum allowed
by the relevant operator.

Reported-and-tested-by: syzbot+8ed8fc4c57e9dcf23ca6@syzkaller.appspotmail.com
Fixes: 8b796475fd ("net/sched: act_pedit: really ensure the skb is writable")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-16 11:48:30 +01:00
arch parisc architecture fixes for kernel v5.18-rc6 2022-05-08 12:42:05 -07:00
block Revert "block: release rq qos structures for queue without disk" 2022-05-02 10:06:40 -06:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation Devicetree fixes for v5.18, part 3: 2022-05-05 15:50:27 -07:00
drivers linux-can-fixes-for-5.18-20220514 2022-05-16 09:39:37 +01:00
fs \n 2022-05-12 10:21:44 -07:00
include Revert "tcp/dccp: get rid of inet_twsk_purge()" 2022-05-13 12:24:12 +01:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel Merge branch 'for-5.18-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2022-05-12 10:42:56 -07:00
lib dim: initialize all struct fields 2022-05-09 17:20:37 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm/readahead: Fix readahead with large folios 2022-05-05 00:47:29 -04:00
net net/sched: act_pedit: sanitize shift argument before usage 2022-05-16 11:48:30 +01:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts objtool: Enable unreachable warnings for CLANG LTO 2022-04-19 21:58:48 +02:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound ASoC: Fixes for v5.18 2022-05-08 10:49:25 +02:00
tools selftests: mptcp: add subflow limits test-cases 2022-05-13 17:04:31 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt Merge branch 'kvm-fixes-for-5.18-rc5' into HEAD 2022-04-29 12:39:34 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap Networking fixes for 5.18-rc7, including fixes from wireless, 2022-05-12 11:51:45 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Networking fixes for 5.18-rc7, including fixes from wireless, 2022-05-12 11:51:45 -07:00
Makefile Linux 5.18-rc6 2022-05-08 13:54:17 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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 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.