* + 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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and is updated there most days
------------------------------------------------------
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
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: + usb-gadgetfs-do-not-warn-about-excessively-large-memory-allocations.patch added to mm-nonmm-unstable branch
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)
0 siblings, 0 replies; 2+ messages in thread
From: Vlastimil Babka (SUSE) @ 2026-08-26 10:31 UTC (permalink / raw)
To: Andrew Morton, mm-commits, stern, stable, gregkh, ziy
On 8/21/26 00:37, Andrew Morton wrote:
> 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
>
> Before you just go and hit "reply", please:
> a) Consider who else should be cc'ed
> b) Prefer to cc a suitable mailing list as well
> c) Ideally: find the original patch on the mailing list and do a
> reply-to-all to that, adding suitable additional cc's
>
> *** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
>
> The -mm tree is included into linux-next via various
> branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
> and is updated there most days
>
> ------------------------------------------------------
> 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>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.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
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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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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