Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

pktgen: fix out-of-bounds access in pgctrl_write()

Browse source 
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>
This commit is contained in:
Mathias Krause 2014-02-21 21:38:34 +01:00 committed by David S. Miller
parent 8bfdfbc188
commit 20b0c718c3
1 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
net/core/pktgen.c
View file

@ -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);