linux/drivers/isdn
Eric Dumazet d63967e475 isdn: fix kernel-infoleak in capi_unlocked_ioctl
Since capi_ioctl() copies 64 bytes after calling
capi20_get_manufacturer() we need to ensure to not leak
information to user.

BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
CPU: 0 PID: 11245 Comm: syz-executor633 Not tainted 4.20.0-rc7+ #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 kmsan_internal_check_memory+0x9d4/0xb00 mm/kmsan/kmsan.c:704
 kmsan_copy_to_user+0xab/0xc0 mm/kmsan/kmsan_hooks.c:601
 _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
 capi_ioctl include/linux/uaccess.h:177 [inline]
 capi_unlocked_ioctl+0x1a0b/0x1bf0 drivers/isdn/capi/capi.c:939
 do_vfs_ioctl+0xebd/0x2bf0 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x440019
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdd4659fb8 EFLAGS: 00000213 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440019
RDX: 0000000020000080 RSI: 00000000c0044306 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000213 R12: 00000000004018a0
R13: 0000000000401930 R14: 0000000000000000 R15: 0000000000000000

Local variable description: ----data.i@capi_unlocked_ioctl
Variable was created at:
 capi_ioctl drivers/isdn/capi/capi.c:747 [inline]
 capi_unlocked_ioctl+0x82/0x1bf0 drivers/isdn/capi/capi.c:939
 do_vfs_ioctl+0xebd/0x2bf0 fs/ioctl.c:46

Bytes 12-63 of 64 are uninitialized
Memory access of size 64 starts at ffff88807ac5fce8
Data copied to user address 0000000020000080

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-02 10:31:39 -08:00
..
capi isdn: fix kernel-infoleak in capi_unlocked_ioctl 2019-01-02 10:31:39 -08:00
divert vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
gigaset Merge branch 'work.tty-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-10-24 14:43:41 +01:00
hardware PCI: add USR vendor id and use it in r8169 and w6692 driver 2018-11-11 14:00:05 -08:00
hisax isdn: hisax: hfc_pci: Fix a possible concurrency use-after-free bug in HFCPCI_l1hw() 2018-12-28 21:27:31 -08:00
hysdn isdn: mark expected switch fall-throughs 2018-07-04 22:17:32 +09:00
i4l isdn_tty: TCSBRK{,P} won't reach ->ioctl() 2018-10-13 00:50:45 -04:00
isdnloop isdnloop: Convert timers to use timer_setup() 2017-10-18 12:40:25 +01:00
mISDN Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-01 19:58:52 -07:00
Kconfig tty: Added a CONFIG_TTY option to allow removal of TTY 2013-01-18 16:15:27 -08:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00