[PATCH] soc: apple: rtkit: Fix use-after-free in apple_rtkit_crashlog_rx()
From: Harshit Mogalapalli <hidden>
Date: 2025-02-12 08:59:53
Also in:
asahi, kernel-janitors, lkml
Subsystem:
arm/apple machine support, the rest · Maintainers:
Sven Peter, Janne Grunau, Linus Torvalds
This code calls kfree(bfr); and then passes "bfr" to rtk->ops->crashed()
which is a use after free. The ->crashed function pointer is implemented
by apple_nvme_rtkit_crashed() and it doesn't use the "bfr" pointer so
this doesn't cause a problem. But it still looks sketchy as can be.
Fix this by moving kfree() after the last usage of bfr.
Fixes: c559645f343a ("soc: apple: rtkit: Pass the crashlog to the crashed() callback")
Signed-off-by: Harshit Mogalapalli <redacted>
---
This is based on static analysis with smatch, only compile tested.
---
drivers/soc/apple/rtkit.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/soc/apple/rtkit.c b/drivers/soc/apple/rtkit.c
index 4b0783091a92..1ccec7ba640c 100644
--- a/drivers/soc/apple/rtkit.c
+++ b/drivers/soc/apple/rtkit.c@@ -360,7 +360,6 @@ static void apple_rtkit_crashlog_rx(struct apple_rtkit *rtk, u64 msg) apple_rtkit_memcpy(rtk, bfr, &rtk->crashlog_buffer, 0, rtk->crashlog_buffer.size); apple_rtkit_crashlog_dump(rtk, bfr, rtk->crashlog_buffer.size); - kfree(bfr); } else { dev_err(rtk->dev, "RTKit: Couldn't allocate crashlog shadow buffer\n");
@@ -369,6 +368,8 @@ static void apple_rtkit_crashlog_rx(struct apple_rtkit *rtk, u64 msg) rtk->crashed = true; if (rtk->ops->crashed) rtk->ops->crashed(rtk->cookie, bfr, rtk->crashlog_buffer.size); + + kfree(bfr); } static void apple_rtkit_ioreport_rx(struct apple_rtkit *rtk, u64 msg)
--
2.39.3