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Eric Dumazet ee74d0bd43 net/x25: reset state in x25_connect()
In case x25_connect() fails and frees the socket neighbour,
we also need to undo the change done to x25->state.

Before my last bug fix, we had use-after-free so this
patch fixes a latent bug.

syzbot report :

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 16137 Comm: syz-executor.1 Not tainted 5.0.0+ #117
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:x25_write_internal+0x1e8/0xdf0 net/x25/x25_subr.c:173
Code: 00 40 88 b5 e0 fe ff ff 0f 85 01 0b 00 00 48 8b 8b 80 04 00 00 48 ba 00 00 00 00 00 fc ff df 48 8d 79 1c 48 89 fe 48 c1 ee 03 <0f> b6 34 16 48 89 fa 83 e2 07 83 c2 03 40 38 f2 7c 09 40 84 f6 0f
RSP: 0018:ffff888076717a08 EFLAGS: 00010207
RAX: ffff88805f2f2292 RBX: ffff8880a0ae6000 RCX: 0000000000000000
kobject: 'loop5' (0000000018d0d0ee): kobject_uevent_env
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: 000000000000001c
RBP: ffff888076717b40 R08: ffff8880950e0580 R09: ffffed100be5e46d
R10: ffffed100be5e46c R11: ffff88805f2f2363 R12: ffff888065579840
kobject: 'loop5' (0000000018d0d0ee): fill_kobj_path: path = '/devices/virtual/block/loop5'
R13: 1ffff1100ece2f47 R14: 0000000000000013 R15: 0000000000000013
FS:  00007fb88cf43700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9a42a41028 CR3: 0000000087a67000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 x25_release+0xd0/0x340 net/x25/af_x25.c:658
 __sock_release+0xd3/0x2b0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1162
 __fput+0x2df/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 get_signal+0x1961/0x1d50 kernel/signal.c:2388
 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457f29
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb88cf42c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000457f29
RDX: 0000000000000012 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb88cf436d4
R13: 00000000004be462 R14: 00000000004cec98 R15: 00000000ffffffff
Modules linked in:

Fixes: 95d6ebd53c ("net/x25: fix use-after-free in x25_device_event()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: andrew hendry <andrew.hendry@gmail.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-11 15:40:14 -07:00
arch y2038: fix socket.h header inclusion 2019-03-11 11:06:00 -07:00
block for-linus-20190215 2019-02-15 09:12:28 -08:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-03-05 09:09:55 -08:00
Documentation dt-bindings: net: stmmac: remove syscfg clock property 2019-03-08 11:48:19 -08:00
drivers net: thunder: fix a potential NULL pointer dereference 2019-03-11 13:34:31 -07:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs a.out: remove core dumping support 2019-03-05 10:00:35 -08:00
include y2038: fix socket.h header inclusion 2019-03-11 11:06:00 -07:00
init revert "initramfs: cleanup incomplete rootfs" 2019-02-21 09:00:59 -08:00
ipc ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390 2019-01-18 09:33:18 +01:00
kernel bpf: fix replace_map_fd_with_map_ptr's ldimm64 second imm field 2019-03-07 08:47:13 -08:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-04 13:26:15 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm Merge branch 'akpm' (patches from Andrew) 2019-03-01 09:04:59 -08:00
net net/x25: reset state in x25_connect() 2019-03-11 15:40:14 -07:00
samples bpf: hbm: fix spelling mistake "deault" -> "default" 2019-03-07 10:35:00 +01:00
scripts kasan: turn off asan-stack for clang-8 and earlier 2019-03-01 09:02:33 -08:00
security get rid of legacy 'get_ds()' function 2019-03-04 10:50:14 -08:00
sound sound fixes for 5.0 2019-02-20 09:42:52 -08:00
tools bpf, libbpf: fixing leak when kernel does not support btf 2019-03-08 21:16:36 +01:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt kvm: properly check debugfs dentry before using it 2019-02-28 08:57:32 -08:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +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: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap .mailmap: Add Mathieu Othacehe 2019-02-21 11:41:19 +00:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS/MAINTAINERS: Retire parisc-linux.org email domain 2019-02-21 20:16:10 +01:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS appletalk: Add atalk.h header files to MAINTAINERS file 2019-03-06 10:46:43 -08:00
Makefile Linux 5.0 2019-03-03 15:21:29 -08:00
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.