Messages in this thread Patch in this message | | | From | Harsh Prateek Bora <> | Subject | [PATCH v2] Typecasting required for comparing unlike datatypes | Date | Mon, 13 Dec 2010 11:41:35 +0530 |
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The existing code causes the if condition to pass when it should fail on a *64-bit kernel* because of implicit data type conversions. It can be observed by passing pos = -1 and count = some positive number. This results in function returning EOVERFLOW instead of EINVAL.
With this patch, the function returns EINVAL when pos is -1 and count is a positive number. This can be tested by calling sendfile with offset = -1 and count = some positive number on a 64-bit kernel.
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
--- fs/read_write.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c index 431a0ed..a8eabd4 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -38,7 +38,7 @@ __negative_fpos_check(struct file *file, loff_t pos, size_t count) * pos or pos+count is negative here, check overflow. * too big "count" will be caught in rw_verify_area(). */ - if ((pos < 0) && (pos + count < pos)) + if ((pos < 0) && ( (loff_t) (pos + count) < pos)) return -EOVERFLOW; if (file->f_mode & FMODE_UNSIGNED_OFFSET) return 0; -- 1.7.1.1
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