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* + usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch added to mm-nonmm-unstable branch
@ 2026-08-20 22:37 Andrew Morton
  2026-08-26 10:31 ` Vlastimil Babka (SUSE)
  0 siblings, 1 reply; 2+ messages in thread
From: Andrew Morton @ 2026-08-20 22:37 UTC (permalink / raw)
  To: mm-commits, vbabka, stern, stable, gregkh, ziy, akpm


The patch titled
     Subject: USB: gadgetfs: do not WARN about excessively large memory allocations
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: USB: gadgetfs: do not WARN about excessively large memory allocations
Date: Thu, 20 Aug 2026 09:19:12 -0400

GadgetFS passes an excessively large user input len to kmalloc and kmalloc
gives a WARN (see below for details).  Suppress it by passing __GFP_NOWARN
to kmalloc used by both ep_write_iter() and ep_read_iter().  Follow the
same method as commit 4f2629ea67e72 ("USB: usbfs: Don't WARN about
excessively large memory allocations").

kmalloc is used to allocate physically contiguous memory for kernel
allocations.  For requests larger than KMALLOC_MAX_CACHE_SIZE, kmalloc
uses the page allocator and can only support up to KMALLOC_MAX_SIZE.  For
request sizes bigger than KMALLOC_MAX_SIZE, the page allocator can emit a
WARN because kmalloc allocates an order greater than MAX_PAGE_ORDER.

Link: https://lore.kernel.org/DKTTMAS94IMH.2C6ERY0ZIVWVZ@nvidia.com
Fixes: b3c466ce5129 ("page allocator: do not sanity check order in the fast=
 path")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: syzbot+805630f1453e490427fa@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6a820ebc.9ebadd4d.20b15e.001b.GAE@googl=
e.com/
Tested-by: syzbot+805630f1453e490427fa@syzkaller.appspotmail.com
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/usb/gadget/legacy/inode.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/legacy/inode.c~usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations
+++ a/drivers/usb/gadget/legacy/inode.c
@@ -604,7 +604,7 @@ ep_read_iter(struct kiocb *iocb, struct
 		return -EBADMSG;
 	}
 
-	buf = kmalloc(len, GFP_KERNEL);
+	buf = kmalloc(len, GFP_KERNEL | __GFP_NOWARN);
 	if (unlikely(!buf)) {
 		mutex_unlock(&epdata->lock);
 		return -ENOMEM;
@@ -666,7 +666,7 @@ ep_write_iter(struct kiocb *iocb, struct
 		return -EBADMSG;
 	}
 
-	buf = kmalloc(len, GFP_KERNEL);
+	buf = kmalloc(len, GFP_KERNEL | __GFP_NOWARN);
 	if (unlikely(!buf)) {
 		mutex_unlock(&epdata->lock);
 		return -ENOMEM;
_

Patches currently in -mm which might be from ziy@nvidia.com are

mm-huge_memory-use-folios-memcg-inside-__folio_split.patch
xarray-honor-xa_flags_account-in-xas_split_alloc.patch
usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch


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2026-08-20 22:37 + usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch added to mm-nonmm-unstable branch Andrew Morton
2026-08-26 10:31 ` Vlastimil Babka (SUSE)

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