Hello!
On 2/15/2017 12:12 PM, DongCV wrote:
In qspi_transfer_in(), when receiving the last n (or len) bytes of data,
1 bogus byte was written in the receive buffer.
This code leads to a buffer overflow.
"jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40000: 0x1900 instead
jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x03b40004: 0x000c instead"
The error message above happens when trying to mount, unmount, and remount a jffs2-formatted device.
This patch removed the bogus write and for clearer to use, here replaced "n" by "len" in
qspi_transfer_in() and qspi_transfer_out() to fixes: 3be09bec42a800d4
"spi: rspi: supports 32bytes buffer for DUAL and QUAD"
I think this is a material for a separate patch.
Here is Geert's comments:
"May I suggest the following:
spi: rspi: Fix bogus received byte in qspi_transfer_in()
When there are less than QSPI_BUFFER_SIZE remaining bytes to be received,
qspi_transfer_in() writes one bogus byte in the receive buffer, possibly
leading to a buffer overflow.
This can be reproduced by mounting, unmounting, and remounting a
jffs2-formatted device, causing lots of warnings like:
jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found
at 0x03b40000: 0x1900 instead
Remove the bogus write to fix this.
It's also a good idea to add a Fixes tag:
Fixes: 3be09bec42a800d4 ("spi: rspi: supports 32bytes buffer for
DUAL and QUAD")
I don't see you adding this tag.
(the code was moved afterwards, but both the origin and the move were
integrated in v4.10-rc1)."
Signed-off-by: DongCV <cv-dong@xxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
[...]
MBR, Sergei
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