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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-01-23 08:34:18 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-29 16:45:29 +0100 |
| commit | 9f6216862a2075474fa985ea3b801c2ac4b41de3 (patch) | |
| tree | 91dbd12d7b628f110c28aefc309db4a9d55170c0 /block/blk-flush.c | |
| parent | 9e2e1a5abccd3a4cd331549399c6ff4008aa4bba (diff) | |
| download | linux-stable-9f6216862a2075474fa985ea3b801c2ac4b41de3.tar.gz linux-stable-9f6216862a2075474fa985ea3b801c2ac4b41de3.tar.bz2 linux-stable-9f6216862a2075474fa985ea3b801c2ac4b41de3.zip | |
lib: Reduce user_access_begin() boundaries in strncpy_from_user() and strnlen_user()
commit ab10ae1c3bef56c29bac61e1201c752221b87b41 upstream.
The range passed to user_access_begin() by strncpy_from_user() and
strnlen_user() starts at 'src' and goes up to the limit of userspace
although reads will be limited by the 'count' param.
On 32 bits powerpc (book3s/32) access has to be granted for each
256Mbytes segment and the cost increases with the number of segments to
unlock.
Limit the range with 'count' param.
Fixes: 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block/blk-flush.c')
0 files changed, 0 insertions, 0 deletions