* [syzbot] WARNING in do_proc_bulk
@ 2021-05-02 20:00 syzbot
2021-05-03 10:25 ` syzbot
0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2021-05-02 20:00 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: acd3d285 Merge tag 'fixes-v5.13' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=123dd1e1d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=7aff3234c75583fe
dashboard link: https://syzkaller.appspot.com/bug?extid=882a85c0c8ec4a3e2281
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com
usb usb9: usbfs: process 9672 (syz-executor.4) did not claim interface 0 before use
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9672 at mm/page_alloc.c:4985 __alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:5020
Modules linked in:
CPU: 0 PID: 9672 Comm: syz-executor.4 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:4985
Code: 00 00 0c 00 0f 85 a7 00 00 00 8b 3c 24 4c 89 f2 44 89 e6 c6 44 24 70 00 48 89 6c 24 58 e8 9b d7 ff ff 49 89 c5 e9 e5 fc ff ff <0f> 0b e9 b0 fd ff ff 89 74 24 14 4c 89 4c 24 08 4c 89 74 24 18 e8
RSP: 0018:ffffc90007cdfa30 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92000f9bf4a RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000040cc0
RBP: 0000000000040cc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b490c1 R11: 0000000000000000 R12: 000000000000000b
R13: 000000000000000b R14: 0000000000000000 R15: 0000000000554e47
FS: 00007fbaa62ba700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005400 CR3: 00000000768f1000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2277
alloc_pages include/linux/gfp.h:561 [inline]
kmalloc_order+0x34/0xf0 mm/slab_common.c:902
kmalloc_order_trace+0x14/0x130 mm/slab_common.c:918
kmalloc include/linux/slab.h:559 [inline]
do_proc_bulk+0x2d4/0x750 drivers/usb/core/devio.c:1221
proc_bulk drivers/usb/core/devio.c:1268 [inline]
usbdev_do_ioctl drivers/usb/core/devio.c:2542 [inline]
usbdev_ioctl+0x586/0x36c0 drivers/usb/core/devio.c:2708
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:1069 [inline]
__se_sys_ioctl fs/ioctl.c:1055 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbaa62ba188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000020000240 RSI: 00000000c0185502 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 0000000000a9fb1f R14: 00007fbaa62ba300 R15: 0000000000022000
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] WARNING in do_proc_bulk
2021-05-02 20:00 [syzbot] WARNING in do_proc_bulk syzbot
@ 2021-05-03 10:25 ` syzbot
2021-05-03 17:53 ` Andrew Morton
0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2021-05-03 10:25 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm, syzkaller-bugs
syzbot has found a reproducer for the following issue on:
HEAD commit: d2b6f8a1 Merge tag 'xfs-5.13-merge-3' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1746d3e1d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=65c207250bba4efe
dashboard link: https://syzkaller.appspot.com/bug?extid=882a85c0c8ec4a3e2281
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107f7893d00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ae7ca5d00000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com
usb usb9: usbfs: process 8586 (syz-executor862) did not claim interface 0 before use
------------[ cut here ]------------
WARNING: CPU: 1 PID: 8586 at mm/page_alloc.c:4985 __alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:5020
Modules linked in:
CPU: 0 PID: 8586 Comm: syz-executor862 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:4985
Code: 00 00 0c 00 0f 85 a7 00 00 00 8b 3c 24 4c 89 f2 44 89 e6 c6 44 24 70 00 48 89 6c 24 58 e8 9b d7 ff ff 49 89 c5 e9 e5 fc ff ff <0f> 0b e9 b0 fd ff ff 89 74 24 14 4c 89 4c 24 08 4c 89 74 24 18 e8
RSP: 0018:ffffc90001f57a30 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff920003eaf4a RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000040cc0
RBP: 0000000000040cc0 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81b51b41 R11: 0000000000000000 R12: 000000000000000b
R13: 000000000000000b R14: 0000000000000000 R15: 0000000000554e47
FS: 0000000002293300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2526f7008 CR3: 000000001d80b000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2277
alloc_pages include/linux/gfp.h:561 [inline]
kmalloc_order+0x34/0xf0 mm/slab_common.c:906
kmalloc_order_trace+0x14/0x130 mm/slab_common.c:922
kmalloc include/linux/slab.h:561 [inline]
do_proc_bulk+0x2d4/0x750 drivers/usb/core/devio.c:1221
proc_bulk drivers/usb/core/devio.c:1268 [inline]
usbdev_do_ioctl drivers/usb/core/devio.c:2542 [inline]
usbdev_ioctl+0x586/0x36c0 drivers/usb/core/devio.c:2708
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:1069 [inline]
__se_sys_ioctl fs/ioctl.c:1055 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4450c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00000000005cfd98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004450c9
RDX: 0000000020000240 RSI: 00000000c0185502 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 00000000005cfdcc
R13: 00000000005cfe00 R14: 00000000005cfde0 R15: 0000000000000005
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] WARNING in do_proc_bulk
2021-05-03 10:25 ` syzbot
@ 2021-05-03 17:53 ` Andrew Morton
2021-05-03 18:56 ` Alan Stern
0 siblings, 1 reply; 7+ messages in thread
From: Andrew Morton @ 2021-05-03 17:53 UTC (permalink / raw)
To: syzbot
Cc: linux-kernel, linux-mm, syzkaller-bugs, Greg Kroah-Hartman, linux-usb
(cc usb peeps)
On Mon, 03 May 2021 03:25:21 -0700 syzbot <syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com> wrote:
> syzbot has found a reproducer for the following issue on:
Thanks.
> HEAD commit: d2b6f8a1 Merge tag 'xfs-5.13-merge-3' of git://git.kernel...
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1746d3e1d00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=65c207250bba4efe
> dashboard link: https://syzkaller.appspot.com/bug?extid=882a85c0c8ec4a3e2281
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107f7893d00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ae7ca5d00000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com
>
> usb usb9: usbfs: process 8586 (syz-executor862) did not claim interface 0 before use
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 8586 at mm/page_alloc.c:4985 __alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:5020
> Modules linked in:
> CPU: 0 PID: 8586 Comm: syz-executor862 Not tainted 5.12.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:__alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:4985
> Code: 00 00 0c 00 0f 85 a7 00 00 00 8b 3c 24 4c 89 f2 44 89 e6 c6 44 24 70 00 48 89 6c 24 58 e8 9b d7 ff ff 49 89 c5 e9 e5 fc ff ff <0f> 0b e9 b0 fd ff ff 89 74 24 14 4c 89 4c 24 08 4c 89 74 24 18 e8
> RSP: 0018:ffffc90001f57a30 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 1ffff920003eaf4a RCX: 0000000000000000
> RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000040cc0
> RBP: 0000000000040cc0 R08: 0000000000000000 R09: 0000000000000000
> R10: ffffffff81b51b41 R11: 0000000000000000 R12: 000000000000000b
> R13: 000000000000000b R14: 0000000000000000 R15: 0000000000554e47
> FS: 0000000002293300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fd2526f7008 CR3: 000000001d80b000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2277
> alloc_pages include/linux/gfp.h:561 [inline]
> kmalloc_order+0x34/0xf0 mm/slab_common.c:906
> kmalloc_order_trace+0x14/0x130 mm/slab_common.c:922
> kmalloc include/linux/slab.h:561 [inline]
> do_proc_bulk+0x2d4/0x750 drivers/usb/core/devio.c:1221
> proc_bulk drivers/usb/core/devio.c:1268 [inline]
> usbdev_do_ioctl drivers/usb/core/devio.c:2542 [inline]
> usbdev_ioctl+0x586/0x36c0 drivers/usb/core/devio.c:2708
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:1069 [inline]
> __se_sys_ioctl fs/ioctl.c:1055 [inline]
> __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
> do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
> entry_SYSCALL_64_after_hwframe+0x44/0xae
do_proc_bulk() is asking kmalloc for more than MAX_ORDER bytes, in
tbuf = kmalloc(len1, GFP_KERNEL);
> RIP: 0033:0x4450c9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00000000005cfd98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004450c9
> RDX: 0000000020000240 RSI: 00000000c0185502 RDI: 0000000000000004
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000005 R11: 0000000000000246 R12: 00000000005cfdcc
> R13: 00000000005cfe00 R14: 00000000005cfde0 R15: 0000000000000005
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] WARNING in do_proc_bulk
2021-05-03 17:53 ` Andrew Morton
@ 2021-05-03 18:56 ` Alan Stern
2021-05-03 19:24 ` Andrew Morton
0 siblings, 1 reply; 7+ messages in thread
From: Alan Stern @ 2021-05-03 18:56 UTC (permalink / raw)
To: Andrew Morton
Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs,
Greg Kroah-Hartman, linux-usb
On Mon, May 03, 2021 at 10:53:51AM -0700, Andrew Morton wrote:
> (cc usb peeps)
>
> On Mon, 03 May 2021 03:25:21 -0700 syzbot <syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com> wrote:
>
> > syzbot has found a reproducer for the following issue on:
>
> Thanks.
>
> > HEAD commit: d2b6f8a1 Merge tag 'xfs-5.13-merge-3' of git://git.kernel...
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1746d3e1d00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=65c207250bba4efe
> > dashboard link: https://syzkaller.appspot.com/bug?extid=882a85c0c8ec4a3e2281
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107f7893d00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ae7ca5d00000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+882a85c0c8ec4a3e2281@syzkaller.appspotmail.com
> >
> > usb usb9: usbfs: process 8586 (syz-executor862) did not claim interface 0 before use
> > ------------[ cut here ]------------
> > WARNING: CPU: 1 PID: 8586 at mm/page_alloc.c:4985 __alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:5020
> > Modules linked in:
> > CPU: 0 PID: 8586 Comm: syz-executor862 Not tainted 5.12.0-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > RIP: 0010:__alloc_pages_nodemask+0x5fd/0x730 mm/page_alloc.c:4985
> > Code: 00 00 0c 00 0f 85 a7 00 00 00 8b 3c 24 4c 89 f2 44 89 e6 c6 44 24 70 00 48 89 6c 24 58 e8 9b d7 ff ff 49 89 c5 e9 e5 fc ff ff <0f> 0b e9 b0 fd ff ff 89 74 24 14 4c 89 4c 24 08 4c 89 74 24 18 e8
> > RSP: 0018:ffffc90001f57a30 EFLAGS: 00010246
> > RAX: 0000000000000000 RBX: 1ffff920003eaf4a RCX: 0000000000000000
> > RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000040cc0
> > RBP: 0000000000040cc0 R08: 0000000000000000 R09: 0000000000000000
> > R10: ffffffff81b51b41 R11: 0000000000000000 R12: 000000000000000b
> > R13: 000000000000000b R14: 0000000000000000 R15: 0000000000554e47
> > FS: 0000000002293300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 00007fd2526f7008 CR3: 000000001d80b000 CR4: 00000000001506f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > alloc_pages_current+0x18c/0x2a0 mm/mempolicy.c:2277
> > alloc_pages include/linux/gfp.h:561 [inline]
> > kmalloc_order+0x34/0xf0 mm/slab_common.c:906
> > kmalloc_order_trace+0x14/0x130 mm/slab_common.c:922
> > kmalloc include/linux/slab.h:561 [inline]
> > do_proc_bulk+0x2d4/0x750 drivers/usb/core/devio.c:1221
> > proc_bulk drivers/usb/core/devio.c:1268 [inline]
> > usbdev_do_ioctl drivers/usb/core/devio.c:2542 [inline]
> > usbdev_ioctl+0x586/0x36c0 drivers/usb/core/devio.c:2708
> > vfs_ioctl fs/ioctl.c:51 [inline]
> > __do_sys_ioctl fs/ioctl.c:1069 [inline]
> > __se_sys_ioctl fs/ioctl.c:1055 [inline]
> > __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
> > do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
> > entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> do_proc_bulk() is asking kmalloc for more than MAX_ORDER bytes, in
>
> tbuf = kmalloc(len1, GFP_KERNEL);
This doesn't seem to be a bug. do_proc_bulk is simply trying to
allocate a kernel buffer for data passed to/from userspace. If a user
wants too much space all at once, that's their problem.
As far as I know, the kmalloc API doesn't require the caller to filter
out requests for more the MAX_ORDER bytes. Only to be prepared to
handle failures -- which do_proc_bulk is all set for.
Am I wrong about this? Should we add __GFP_NOWARN to the gfp flags?
Alan Stern
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] WARNING in do_proc_bulk
2021-05-03 18:56 ` Alan Stern
@ 2021-05-03 19:24 ` Andrew Morton
2021-05-04 0:47 ` Alan Stern
0 siblings, 1 reply; 7+ messages in thread
From: Andrew Morton @ 2021-05-03 19:24 UTC (permalink / raw)
To: Alan Stern
Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs,
Greg Kroah-Hartman, linux-usb
On Mon, 3 May 2021 14:56:14 -0400 Alan Stern <stern@rowland.harvard.edu> wrote:
> >
> > do_proc_bulk() is asking kmalloc for more than MAX_ORDER bytes, in
> >
> > tbuf = kmalloc(len1, GFP_KERNEL);
>
> This doesn't seem to be a bug. do_proc_bulk is simply trying to
> allocate a kernel buffer for data passed to/from userspace. If a user
> wants too much space all at once, that's their problem.
>
> As far as I know, the kmalloc API doesn't require the caller to filter
> out requests for more the MAX_ORDER bytes. Only to be prepared to
> handle failures -- which do_proc_bulk is all set for.
>
> Am I wrong about this? Should we add __GFP_NOWARN to the gfp flags?
Yes, if the oversized request is a can-happen and the resulting error is handled
appropriately, __GFP_NOWARN is the way to go.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] WARNING in do_proc_bulk
2021-05-03 19:24 ` Andrew Morton
@ 2021-05-04 0:47 ` Alan Stern
2021-05-04 1:07 ` syzbot
0 siblings, 1 reply; 7+ messages in thread
From: Alan Stern @ 2021-05-04 0:47 UTC (permalink / raw)
To: Andrew Morton
Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs,
Greg Kroah-Hartman, linux-usb
On Mon, May 03, 2021 at 12:24:28PM -0700, Andrew Morton wrote:
> On Mon, 3 May 2021 14:56:14 -0400 Alan Stern <stern@rowland.harvard.edu> wrote:
>
> > >
> > > do_proc_bulk() is asking kmalloc for more than MAX_ORDER bytes, in
> > >
> > > tbuf = kmalloc(len1, GFP_KERNEL);
> >
> > This doesn't seem to be a bug. do_proc_bulk is simply trying to
> > allocate a kernel buffer for data passed to/from userspace. If a user
> > wants too much space all at once, that's their problem.
> >
> > As far as I know, the kmalloc API doesn't require the caller to filter
> > out requests for more the MAX_ORDER bytes. Only to be prepared to
> > handle failures -- which do_proc_bulk is all set for.
> >
> > Am I wrong about this? Should we add __GFP_NOWARN to the gfp flags?
>
> Yes, if the oversized request is a can-happen and the resulting error is handled
> appropriately, __GFP_NOWARN is the way to go.
Okay, let's see how this does.
Alan Stern
#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d2b6f8a1
Index: usb-devel/drivers/usb/core/devio.c
===================================================================
--- usb-devel.orig/drivers/usb/core/devio.c
+++ usb-devel/drivers/usb/core/devio.c
@@ -1218,7 +1218,12 @@ static int do_proc_bulk(struct usb_dev_s
ret = usbfs_increase_memory_usage(len1 + sizeof(struct urb));
if (ret)
return ret;
- tbuf = kmalloc(len1, GFP_KERNEL);
+
+ /*
+ * len1 can be almost arbitrarily large. Don't WARN if it's
+ * too big, just fail the request.
+ */
+ tbuf = kmalloc(len1, GFP_KERNEL | __GFP_NOWARN);
if (!tbuf) {
ret = -ENOMEM;
goto done;
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-05-04 1:07 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2021-05-02 20:00 [syzbot] WARNING in do_proc_bulk syzbot
2021-05-03 10:25 ` syzbot
2021-05-03 17:53 ` Andrew Morton
2021-05-03 18:56 ` Alan Stern
2021-05-03 19:24 ` Andrew Morton
2021-05-04 0:47 ` Alan Stern
2021-05-04 1:07 ` syzbot
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