Patch "i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data." has been added to the 6.6-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data.

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     i3c-master-mipi-i3c-hci-fix-a-kernel-panic-for-acces.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0bb998f00758daf9aaeddcbd2201011e3ee41e0c
Author: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
Date:   Mon Oct 23 16:02:37 2023 +0800

    i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data.
    
    [ Upstream commit b53e9758a31c683fc8615df930262192ed5f034b ]
    
    The `i3c_master_bus_init` function may attach the I2C devices before the
    I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used
    before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails,
    the DAT `cleanup` will execute before the device is detached, which will
    execue DAT `free_entry` function. The above scenario can cause the driver
    to use DAT_data when it is NULL.
    
    Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20231023080237.560936-1-billy_tsai@xxxxxxxxxxxxxx
    Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
index 97bb49ff5b53b..47b9b4d4ed3fc 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dat_v1.c
@@ -64,15 +64,17 @@ static int hci_dat_v1_init(struct i3c_hci *hci)
 		return -EOPNOTSUPP;
 	}
 
-	/* use a bitmap for faster free slot search */
-	hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL);
-	if (!hci->DAT_data)
-		return -ENOMEM;
-
-	/* clear them */
-	for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) {
-		dat_w0_write(dat_idx, 0);
-		dat_w1_write(dat_idx, 0);
+	if (!hci->DAT_data) {
+		/* use a bitmap for faster free slot search */
+		hci->DAT_data = bitmap_zalloc(hci->DAT_entries, GFP_KERNEL);
+		if (!hci->DAT_data)
+			return -ENOMEM;
+
+		/* clear them */
+		for (dat_idx = 0; dat_idx < hci->DAT_entries; dat_idx++) {
+			dat_w0_write(dat_idx, 0);
+			dat_w1_write(dat_idx, 0);
+		}
 	}
 
 	return 0;
@@ -87,7 +89,13 @@ static void hci_dat_v1_cleanup(struct i3c_hci *hci)
 static int hci_dat_v1_alloc_entry(struct i3c_hci *hci)
 {
 	unsigned int dat_idx;
+	int ret;
 
+	if (!hci->DAT_data) {
+		ret = hci_dat_v1_init(hci);
+		if (ret)
+			return ret;
+	}
 	dat_idx = find_first_zero_bit(hci->DAT_data, hci->DAT_entries);
 	if (dat_idx >= hci->DAT_entries)
 		return -ENOENT;
@@ -103,7 +111,8 @@ static void hci_dat_v1_free_entry(struct i3c_hci *hci, unsigned int dat_idx)
 {
 	dat_w0_write(dat_idx, 0);
 	dat_w1_write(dat_idx, 0);
-	__clear_bit(dat_idx, hci->DAT_data);
+	if (hci->DAT_data)
+		__clear_bit(dat_idx, hci->DAT_data);
 }
 
 static void hci_dat_v1_set_dynamic_addr(struct i3c_hci *hci,



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux