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| author | David Howells <dhowells@redhat.com> | 2016-10-26 15:01:54 +0100 |
|---|---|---|
| committer | Gerrit - the friendly Code Review server <code-review@localhost> | 2017-01-10 14:14:57 -0800 |
| commit | 7e5d3e2def4b5dd7ac45f2b4b6116b22668af2b6 (patch) | |
| tree | 68a4e4db5b35cfb74eb025dbce066a24e9b1c3b2 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | 0a8e939a4e57d86da88c9856cd266447fc45ea85 (diff) | |
KEYS: Fix short sprintf buffer in /proc/keys show function
This fixes CVE-2016-7042.
Fix a short sprintf buffer in proc_keys_show(). If the gcc stack protector
is turned on, this can cause a panic due to stack corruption.
The problem is that xbuf[] is not big enough to hold a 64-bit timeout
rendered as weeks:
(gdb) p 0xffffffffffffffffULL/(60*60*24*7)
$2 = 30500568904943
That's 14 chars plus NUL, not 11 chars plus NUL.
Expand the buffer to 16 chars.
I think the unpatched code apparently works if the stack-protector is not
enabled because on a 32-bit machine the buffer won't be overflowed and on a
64-bit machine there's a 64-bit aligned pointer at one side and an int that
isn't checked again on the other side.
The panic incurred looks something like:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81352ebe
CPU: 0 PID: 1692 Comm: reproducer Not tainted 4.7.2-201.fc24.x86_64 #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
0000000000000086 00000000fbbd2679 ffff8800a044bc00 ffffffff813d941f
ffffffff81a28d58 ffff8800a044bc98 ffff8800a044bc88 ffffffff811b2cb6
ffff880000000010 ffff8800a044bc98 ffff8800a044bc30 00000000fbbd2679
Call Trace:
[<ffffffff813d941f>] dump_stack+0x63/0x84
[<ffffffff811b2cb6>] panic+0xde/0x22a
[<ffffffff81352ebe>] ? proc_keys_show+0x3ce/0x3d0
[<ffffffff8109f7f9>] __stack_chk_fail+0x19/0x30
[<ffffffff81352ebe>] proc_keys_show+0x3ce/0x3d0
[<ffffffff81350410>] ? key_validate+0x50/0x50
[<ffffffff8134db30>] ? key_default_cmp+0x20/0x20
[<ffffffff8126b31c>] seq_read+0x2cc/0x390
[<ffffffff812b6b12>] proc_reg_read+0x42/0x70
[<ffffffff81244fc7>] __vfs_read+0x37/0x150
[<ffffffff81357020>] ? security_file_permission+0xa0/0xc0
[<ffffffff81246156>] vfs_read+0x96/0x130
[<ffffffff81247635>] SyS_read+0x55/0xc0
[<ffffffff817eb872>] entry_SYSCALL_64_fastpath+0x1a/0xa4
Change-Id: I23554b54eb9b82f44554a3ef620200de9f6ea55a
Reported-by: Ondrej Kozina <okozina@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ondrej Kozina <okozina@redhat.com>
cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
Git-repo: http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git
Git-commit: 03dab869b7b239c4e013ec82aea22e181e441cfc
Signed-off-by: Dennis Cagle <d-cagle@codeaurora.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions