This is a note to let you know that I've just added the patch titled i3c: master: dw: check return of dw_i3c_master_get_free_pos() to the 5.15-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-dw-check-return-of-dw_i3c_master_get_free.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5170d69923c048228abe57909b2c1ec6e2c334c9 Author: Tom Rix <trix@xxxxxxxxxx> Date: Sat Jan 8 07:09:48 2022 -0800 i3c: master: dw: check return of dw_i3c_master_get_free_pos() [ Upstream commit 13462ba1815db5a96891293a9cfaa2451f7bd623 ] Clang static analysis reports this problem dw-i3c-master.c:799:9: warning: The result of the left shift is undefined because the left operand is negative COMMAND_PORT_DEV_INDEX(pos) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ pos can be negative because dw_i3c_master_get_free_pos() can return an error. So check for an error. Fixes: 1dd728f5d4d4 ("i3c: master: Add driver for Synopsys DesignWare IP") Signed-off-by: Tom Rix <trix@xxxxxxxxxx> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220108150948.3988790-1-trix@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c index 03a368da51b95..51a8608203de7 100644 --- a/drivers/i3c/master/dw-i3c-master.c +++ b/drivers/i3c/master/dw-i3c-master.c @@ -793,6 +793,10 @@ static int dw_i3c_master_daa(struct i3c_master_controller *m) return -ENOMEM; pos = dw_i3c_master_get_free_pos(master); + if (pos < 0) { + dw_i3c_master_free_xfer(xfer); + return pos; + } cmd = &xfer->cmds[0]; cmd->cmd_hi = 0x1; cmd->cmd_lo = COMMAND_PORT_DEV_COUNT(master->maxdevs - pos) |