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| author |   Jann Horn <jannh@google.com> | 2018-06-20 18:33:45 +0200 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2018-06-26 16:48:23 +0200 |
| commit | dffd22aed2aa1e804bccf19b30a421e89ee2ae61 (patch) | |
| tree | 527ee8d7048c5e0df7398273a7bac5cac5bda6c5 /net/netfilter/nf_log.c | |
| parent | netfilter: nf_ct_helper: Fix possible panic after nf_conntrack_helper_unregister (diff) | |
| download | linux-dev-dffd22aed2aa1e804bccf19b30a421e89ee2ae61.tar.xz linux-dev-dffd22aed2aa1e804bccf19b30a421e89ee2ae61.zip | |
netfilter: nf_log: fix uninit read in nf_log_proc_dostring
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>
Diffstat (limited to 'net/netfilter/nf_log.c')
| -rw-r--r-- | net/netfilter/nf_log.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index 426457047578..2c47f9ec3511 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -424,6 +424,10 @@ static int nf_log_proc_dostring(struct ctl_table *table, int write, 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) |