Hello!
These patches fix a few memory leaks in HID report descriptor fixups.
FWIW, a good ad-hoc way to look for usages of allocation functions in
these is:
awk '/static.*report_fixup.*/,/^}/ { print FILENAME, $0 }' drivers/hid/hid-*.c \
| grep -E '(malloc|kzalloc|kcalloc|kmemdup)'
The devm_* variants are safe in this context, because they tie the
allocated memory to the lifetime of the driver.
For transparency, I generated these commits with Gemini-CLI,
starting with this prompt:
We are working in the Linux kernel. In the HID drivers in
`drivers/hid/hid-*.c`, the `report_fixup` driver hook is a function
that gets a byte buffer (with size) as input and that may modify that
byte buffer, and optionally return a pointer to a new byte buffer and
update the size. The returned value is *not* memory-managed by the
caller though and will not be freed subsequently. When the
`report_fixup` implementation allocates a new buffer and returns that,
that will not get freed by the caller. Validate this assessment and
fix up all HID drivers where that mistake is made.
(and then a little bit of additional nudging for the details).
—Günther
---
Revision history:
V2:
* Add a commit documenting the memory allocation properties of report_fixup().
* Reword the commit message for the three memory leak fixes.
V1: Original patch set
https://lore.kernel.org/all/20260217160125.1097578-1-gnoack@google.com/
Günther Noack (4):
HID: Document memory allocation properties of report_fixup()
HID: apple: avoid memory leak in apple_report_fixup()
HID: magicmouse: avoid memory leak in magicmouse_report_fixup()
HID: asus: avoid memory leak in asus_report_fixup()
drivers/hid/hid-apple.c | 4 +---
drivers/hid/hid-asus.c | 15 +++++++++++----
drivers/hid/hid-magicmouse.c | 4 +---
include/linux/hid.h | 6 ++++++
4 files changed, 19 insertions(+), 10 deletions(-)
--
2.53.0.371.g1d285c8824-goog