| From foo@baz Wed Aug 22 09:42:09 CEST 2018 |
| From: Jann Horn <jannh@google.com> |
| Date: Wed, 20 Jun 2018 18:33:45 +0200 |
| Subject: netfilter: nf_log: fix uninit read in nf_log_proc_dostring |
| |
| From: Jann Horn <jannh@google.com> |
| |
| [ Upstream commit dffd22aed2aa1e804bccf19b30a421e89ee2ae61 ] |
| |
| When proc_dostring() is called with a non-zero offset in strict mode, it |
| doesn't just write to the ->data buffer, it also reads. Make sure it |
| doesn't read uninitialized data. |
| |
| Fixes: c6ac37d8d884 ("netfilter: nf_log: fix error on write NONE to [...]") |
| Signed-off-by: Jann Horn <jannh@google.com> |
| Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/netfilter/nf_log.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/net/netfilter/nf_log.c |
| +++ b/net/netfilter/nf_log.c |
| @@ -426,6 +426,10 @@ static int nf_log_proc_dostring(struct c |
| if (write) { |
| struct ctl_table tmp = *table; |
| |
| + /* proc_dostring() can append to existing strings, so we need to |
| + * initialize it as an empty string. |
| + */ |
| + buf[0] = '\0'; |
| tmp.data = buf; |
| r = proc_dostring(&tmp, write, buffer, lenp, ppos); |
| if (r) |
