[PATCH 6.19 276/781] rust: pwm: Fix potential memory leak on init error

Greg Kroah-Hartman
2026-02-25T01:31:56Z

From: Kari Argillander <kari.argillander@gmail.com>

[ Upstream commit a2633dc243c35754a0c2270131d8a199c987c9bf ]

When initializing a PWM chip using pwmchip_alloc(), the allocated device
owns an initial reference that must be released on all error paths.

If __pinned_init() were to fail, the allocated pwm_chip would currently
leak because the error path returns without calling pwmchip_put().

Fixes: 7b3dce814a15 ("rust: pwm: Add Kconfig and basic data structures")
Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Acked-by: Michal Wilczynski <m.wilczynski@samsung.com>
Link: https://patch.msgid.link/20260102-pwm-rust-v2-1-2702ce57d571@gmail.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
rust/kernel/pwm.rs | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/pwm.rs b/rust/kernel/pwm.rs
index cb00f8a8765c8..2ba9cfd02bfdb 100644
--- a/rust/kernel/pwm.rs
+++ b/rust/kernel/pwm.rs
@@ -601,7 +601,11 @@ pub fn new(
let drvdata_ptr = unsafe { bindings::pwmchip_get_drvdata(c_chip_ptr) };

// SAFETY: We construct the `T` object in-place in the allocated private memory.
- unsafe { data.__pinned_init(drvdata_ptr.cast())? };
+ unsafe { data.__pinned_init(drvdata_ptr.cast()) }.inspect_err(|_| {
+ // SAFETY: It is safe to call `pwmchip_put()` with a valid pointer obtained
+ // from `pwmchip_alloc()`. We will not use pointer after this.
+ unsafe { bindings::pwmchip_put(c_chip_ptr) }
+ })?;

// SAFETY: `c_chip_ptr` points to a valid chip.
unsafe {
--
2.51.0