]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
usb: raw-gadget: cap raw_io transfer length to KMALLOC_MAX_SIZE
authorGopi Krishna Menon <krishnagopi487@gmail.com>
Tue, 28 Oct 2025 16:56:57 +0000 (22:26 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 18 Dec 2025 12:55:04 +0000 (13:55 +0100)
commitef065c4d4a2d84a010dd21f1e13a3a0b4a099840
treefdfc467ea54a1b42f89a2c8884b05cb656991d8b
parentf8408e1e54ddac7fc5aad716101027c287601174
usb: raw-gadget: cap raw_io transfer length to KMALLOC_MAX_SIZE

[ Upstream commit a5160af78be7fcf3ade6caab0a14e349560c96d7 ]

The previous commit removed the PAGE_SIZE limit on transfer length of
raw_io buffer in order to avoid any problems with emulating USB devices
whose full configuration descriptor exceeds PAGE_SIZE in length. However
this also removes the upperbound on user supplied length, allowing very
large values to be passed to the allocator.

syzbot on fuzzing the transfer length with very large value (1.81GB)
results in kmalloc() to fall back to the page allocator, which triggers
a kernel warning as the page allocator cannot handle allocations more
than MAX_PAGE_ORDER/KMALLOC_MAX_SIZE.

Since there is no limit imposed on the size of buffer for both control
and non control transfers, cap the raw_io transfer length to
KMALLOC_MAX_SIZE and return -EINVAL for larger transfer length to
prevent any warnings from the page allocator.

Fixes: 37b9dd0d114a ("usb: raw-gadget: do not limit transfer length")
Tested-by: syzbot+d8fd35fa6177afa8c92b@syzkaller.appspotmail.com
Reported-by: syzbot+d8fd35fa6177afa8c92b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68fc07a0.a70a0220.3bf6c6.01ab.GAE@google.com/
Signed-off-by: Gopi Krishna Menon <krishnagopi487@gmail.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://patch.msgid.link/20251028165659.50962-1-krishnagopi487@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/usb/gadget/legacy/raw_gadget.c