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author | David Jeffery <dhjeffery@gmail.com> | 2012-04-11 18:14:25 +0200 |
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committer | James Bottomley <JBottomley@Parallels.com> | 2012-05-10 09:32:34 +0200 |
commit | 7c018a901c3fef2af9d713ba849e8e52eb82dde1 (patch) | |
tree | d247f779ca728f9bc2753f78c027ba599626ed5c /drivers/scsi/st.h | |
parent | [SCSI] bfa: Update the MAINTAINERS file. (diff) | |
download | linux-7c018a901c3fef2af9d713ba849e8e52eb82dde1.tar.xz linux-7c018a901c3fef2af9d713ba849e8e52eb82dde1.zip |
[SCSI] st: fix memory leak with >1MB tape I/O
There is a memory leak in the st driver when sending large enough reads or
writes using st's direct I/O path. As part of mapping the application's
memory, a buffer to hold page pointers is allocated and the count of mapped
pages is stored in field do_dio. A non-zero do_dio marks that direct I/O is
in use.
But do_dio is only 1 byte in size. Mapping 256 4k pages overflows
do_dio and causes it to be set to 0, like direct I/O option was not
used. When the I/O completes, the buffer to hold the page pointers is
not freed, and the page counts of the mapped pages are not reduced.
Every I/O of this size then leaks memory.
The size of do_dio needs to be increased to prevent it wrapping around.
Signed-off-by: David Jeffery <djeffery@redhat.com>
Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to '')
-rw-r--r-- | drivers/scsi/st.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h index ea35632b986c..b548923785ed 100644 --- a/drivers/scsi/st.h +++ b/drivers/scsi/st.h @@ -35,8 +35,8 @@ struct st_request { /* The tape buffer descriptor. */ struct st_buffer { unsigned char dma; /* DMA-able buffer */ - unsigned char do_dio; /* direct i/o set up? */ unsigned char cleared; /* internal buffer cleared after open? */ + unsigned short do_dio; /* direct i/o set up? */ int buffer_size; int buffer_blocks; int buffer_bytes; |