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| author | Vasiliy Kulikov <segoon@openwall.com> | 2011-04-14 19:56:25 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-25 16:45:22 -0700 |
| commit | 5d46f3266728913d05106ee82fb5f043be06eb21 (patch) | |
| tree | fe5fdcc013d3b0b7f648eec6bfdd49360cdf3531 /drivers/staging/tty | |
| parent | 7816c45bf13255157c00fb8aca86cb64d825e878 (diff) | |
| download | kernel_samsung_smdk4412-5d46f3266728913d05106ee82fb5f043be06eb21.zip kernel_samsung_smdk4412-5d46f3266728913d05106ee82fb5f043be06eb21.tar.gz kernel_samsung_smdk4412-5d46f3266728913d05106ee82fb5f043be06eb21.tar.bz2 | |
staging: istallion: fix arbitrary kernel memory reads/writes
stli_brdstats is defined as global variable. After de-BKL-ization in
the patch b4eda9cb48eac1b7 an access to the variable is not serialized
anymore. This leads to the race window between the check and the use
in stli_getbrdstats():
if (copy_from_user(&stli_brdstats, bp, sizeof(combrd_t)))
return -EFAULT;
if (stli_brdstats.brd >= STL_MAXBRDS) <<<
return -ENODEV;
brdp = stli_brds[stli_brdstats.brd]; <<<
If one process calls COM_GETBRDSTATS ioctl() with sane .brd, second
process calls COM_GETBRDSTATS ioctl() with invalid .brd, and the
second process' copy_from_user() executes exactly between the check and
stli_brds[] indexation of the first process, then the first process gets
contents of memory at *stli_brds[stli_brdstats.brd] address. Also
the resulting .nrpanels field may be too big, in this case
stli_brdstats.panels array overflows.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/tty')
| -rw-r--r-- | drivers/staging/tty/istallion.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/tty/istallion.c b/drivers/staging/tty/istallion.c index 0b26627..ca18cbf 100644 --- a/drivers/staging/tty/istallion.c +++ b/drivers/staging/tty/istallion.c @@ -186,7 +186,6 @@ static struct ktermios stli_deftermios = { * re-used for each stats call. */ static comstats_t stli_comstats; -static combrd_t stli_brdstats; static struct asystats stli_cdkstats; /*****************************************************************************/ @@ -4005,6 +4004,7 @@ static int stli_getbrdstats(combrd_t __user *bp) { struct stlibrd *brdp; unsigned int i; + combrd_t stli_brdstats; if (copy_from_user(&stli_brdstats, bp, sizeof(combrd_t))) return -EFAULT; |