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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2015-12-22 17:25:21 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-07 22:43:17 -0800
commitf08b18266c7116e2ec6885dd53a928f580060a71 (patch)
tree90487bb127914a64084190520a3517f1d5137150 /drivers/hwtracing
parent7b3bb0e75395b2f3b0f95d9ae50581e989ba5e4c (diff)
downloadop-kernel-dev-f08b18266c7116e2ec6885dd53a928f580060a71.zip
op-kernel-dev-f08b18266c7116e2ec6885dd53a928f580060a71.tar.gz
stm class: Prevent user-controllable allocations
Currently, the character device write method allocates a temporary buffer for user's data, but the user's data size is not sanitized and can cause arbitrarily large allocations via kzalloc() or an integer overflow that will then result in overwriting kernel memory. This patch trims the input buffer size to avoid these issues. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/stm/core.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 40a8b79..aef8ddb 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -406,6 +406,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
char *kbuf;
int err;
+ if (count + 1 > PAGE_SIZE)
+ count = PAGE_SIZE - 1;
+
/*
* if no m/c have been assigned to this writer up to this
* point, use "default" policy entry
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