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| author | Jean Delvare <jdelvare@suse.de> | 2021-05-25 17:03:36 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2021-05-27 21:56:42 +0200 |
| commit | e4d8716c3dcec47f1557024add24e1f3c09eb24b (patch) | |
| tree | 0d8cdd7bf3fa76dd4bf0d3cd69d3f2e567869db9 | |
| parent | i2c: mpc: implement erratum A-004447 workaround (diff) | |
| download | linux-e4d8716c3dcec47f1557024add24e1f3c09eb24b.tar.xz linux-e4d8716c3dcec47f1557024add24e1f3c09eb24b.zip | |
i2c: i801: Don't generate an interrupt on bus reset
Now that the i2c-i801 driver supports interrupts, setting the KILL bit
in a attempt to recover from a timed out transaction triggers an
interrupt. Unfortunately, the interrupt handler (i801_isr) is not
prepared for this situation and will try to process the interrupt as
if it was signaling the end of a successful transaction. In the case
of a block transaction, this can result in an out-of-range memory
access.
This condition was reproduced several times by syzbot:
https://syzkaller.appspot.com/bug?extid=ed71512d469895b5b34e
https://syzkaller.appspot.com/bug?extid=8c8dedc0ba9e03f6c79e
https://syzkaller.appspot.com/bug?extid=c8ff0b6d6c73d81b610e
https://syzkaller.appspot.com/bug?extid=33f6c360821c399d69eb
https://syzkaller.appspot.com/bug?extid=be15dc0b1933f04b043a
https://syzkaller.appspot.com/bug?extid=b4d3fd1dfd53e90afd79
So disable interrupts while trying to reset the bus. Interrupts will
be enabled again for the following transaction.
Fixes: 636752bcb517 ("i2c-i801: Enable IRQ for SMBus transactions")
Reported-by: syzbot+b4d3fd1dfd53e90afd79@syzkaller.appspotmail.com
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 99d446763530..f9e1c2ceaac0 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -395,11 +395,9 @@ static int i801_check_post(struct i801_priv *priv, int status) dev_err(&priv->pci_dev->dev, "Transaction timeout\n"); /* try to stop the current command */ dev_dbg(&priv->pci_dev->dev, "Terminating the current operation\n"); - outb_p(inb_p(SMBHSTCNT(priv)) | SMBHSTCNT_KILL, - SMBHSTCNT(priv)); + outb_p(SMBHSTCNT_KILL, SMBHSTCNT(priv)); usleep_range(1000, 2000); - outb_p(inb_p(SMBHSTCNT(priv)) & (~SMBHSTCNT_KILL), - SMBHSTCNT(priv)); + outb_p(0, SMBHSTCNT(priv)); /* Check if it worked */ status = inb_p(SMBHSTSTS(priv)); |