| From | Greg Kroah-Hartman <> | Subject | [ 10/46] vfs: missed source of ->f_pos races | Date | Wed, 12 Sep 2012 16:39:00 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
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From: Al Viro <viro@ZenIV.linux.org.uk>
commit 0e665d5d1125f9f4ccff56a75e814f10f88861a2 upstream.
compat_sys_{read,write}v() need the same "pass a copy of file->f_pos" thing as sys_{read,write}{,v}().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/compat.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/fs/compat.c +++ b/fs/compat.c @@ -1177,11 +1177,14 @@ compat_sys_readv(unsigned long fd, const struct file *file; int fput_needed; ssize_t ret; + loff_t pos; file = fget_light(fd, &fput_needed); if (!file) return -EBADF; - ret = compat_readv(file, vec, vlen, &file->f_pos); + pos = file->f_pos; + ret = compat_readv(file, vec, vlen, &pos); + file->f_pos = pos; fput_light(file, fput_needed); return ret; } @@ -1236,11 +1239,14 @@ compat_sys_writev(unsigned long fd, cons struct file *file; int fput_needed; ssize_t ret; + loff_t pos; file = fget_light(fd, &fput_needed); if (!file) return -EBADF; - ret = compat_writev(file, vec, vlen, &file->f_pos); + pos = file->f_pos; + ret = compat_writev(file, vec, vlen, &pos); + file->f_pos = pos; fput_light(file, fput_needed); return ret; }
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