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"
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")
(the code was moved afterwards, but both the origin and the move were
integrated in v4.10-rc1)."
Signed-off-by: DongCV <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
---
drivers/spi/spi-rspi.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 9daf500..bc3c868 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -808,7 +808,7 @@ static int qspi_transfer_out(struct rspi_data *rspi, struct
spi_transfer *xfer)
for (i = 0; i < len; i++)
rspi_write_data(rspi, *tx++);
} else {
- ret = rspi_pio_transfer(rspi, tx, NULL, n);
+ ret = rspi_pio_transfer(rspi, tx, NULL, len);
if (ret < 0)
return ret;
}
@@ -845,10 +845,9 @@ static int qspi_transfer_in(struct rspi_data *rspi, struct
spi_transfer *xfer)
for (i = 0; i < len; i++)
*rx++ = rspi_read_data(rspi);
} else {
- ret = rspi_pio_transfer(rspi, NULL, rx, n);
+ ret = rspi_pio_transfer(rspi, NULL, rx, len);
if (ret < 0)
return ret;
- *rx++ = ret;
}
n -= len;
}
--
1.9.1
