diff options
author | Mathias Krause <minipli@googlemail.com> | 2014-02-21 21:38:34 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-02-24 18:54:25 -0500 |
commit | 20b0c718c3bb122107bebadbb8ecf4bab76fb392 (patch) | |
tree | 1408cdb798aacbb27a42fe735b6658289c6004ec /net | |
parent | 8bfdfbc188ff46f7495ae05a2bc366943b83393f (diff) |
pktgen: fix out-of-bounds access in pgctrl_write()
If a privileged user writes an empty string to /proc/net/pktgen/pgctrl
the code for stripping the (then non-existent) '\n' actually writes the
zero byte at index -1 of data[]. The then still uninitialized array will
very likely fail the command matching tests and the pr_warning() at the
end will therefore leak stack bytes to the kernel log.
Fix those issues by simply ensuring we're passed a non-empty string as
the user API apparently expects a trailing '\n' for all commands.
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/pktgen.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index fdac61cac1bd..cc07c434948a 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -485,6 +485,9 @@ static ssize_t pgctrl_write(struct file *file, const char __user *buf, goto out; } + if (count == 0) + return -EINVAL; + if (count > sizeof(data)) count = sizeof(data); @@ -492,7 +495,7 @@ static ssize_t pgctrl_write(struct file *file, const char __user *buf, err = -EFAULT; goto out; } - data[count - 1] = 0; /* Make string */ + data[count - 1] = 0; /* Strip trailing '\n' and terminate string */ if (!strcmp(data, "stop")) pktgen_stop_all_threads_ifs(pn); |