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authorJean Delvare <jdelvare@suse.de>2021-05-25 17:03:36 +0200
committerWolfram Sang <wsa@kernel.org>2021-05-27 21:56:42 +0200
commite4d8716c3dcec47f1557024add24e1f3c09eb24b (patch)
tree0d8cdd7bf3fa76dd4bf0d3cd69d3f2e567869db9 /drivers/i2c
parent8f0cdec8b5fd94135d643662506ee94ae9e98785 (diff)
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>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-i801.c6
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));