]> err.no Git - linux-2.6/commit
[PATCH] mmaper_kern.c fixes [buffer overruns]
authorAl Viro <viro@parcelfarce.linux.theplanet.co.uk>
Sat, 27 Aug 2005 05:48:15 +0000 (06:48 +0100)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sat, 27 Aug 2005 17:11:40 +0000 (10:11 -0700)
commit6a029a90f5b93e2b50bcbbaef05ef91fa0c1d6b3
treeba62bf7de680c10c00224305d628b484494918a1
parent36676bcbf9f6bcbea9d06e67ee8d04eacde54952
[PATCH] mmaper_kern.c fixes [buffer overruns]

 - copy_from_user() can fail; ->write() must check its return value.

 - severe buffer overruns both in ->read() and ->write() - lseek to the
   end (i.e.  to mmapper_size) and

if (count + *ppos > mmapper_size)
count = count + *ppos - mmapper_size;

   will do absolutely nothing.  Then it will call

copy_to_user(buf,&v_buf[*ppos],count);

   with obvious results (similar for ->write()).

   Fixed by turning read to simple_read_from_buffer() and by doing
   normal limiting of count in ->write().

 - gratitious lock_kernel() in ->mmap() - it's useless there.

 - lots of gratuitous includes.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch/um/drivers/mmapper_kern.c