<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/net, branch v5.15.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>wifi: brcmfmac: Fix potential buffer overflow in brcmf_fweh_event_worker()</title>
<updated>2022-11-10T17:15:43+00:00</updated>
<author>
<name>Dokyung Song</name>
<email>dokyung.song@gmail.com</email>
</author>
<published>2022-10-21T06:13:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7038af4ce95105146d22e461eaa450829f28eeaf'/>
<id>7038af4ce95105146d22e461eaa450829f28eeaf</id>
<content type='text'>
commit 6788ba8aed4e28e90f72d68a9d794e34eac17295 upstream.

This patch fixes an intra-object buffer overflow in brcmfmac that occurs
when the device provides a 'bsscfgidx' equal to or greater than the
buffer size. The patch adds a check that leads to a safe failure if that
is the case.

This fixes CVE-2022-3628.

UBSAN: array-index-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index 52 is out of range for type 'brcmf_if *[16]'
CPU: 0 PID: 1898 Comm: kworker/0:2 Tainted: G           O      5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: events brcmf_fweh_event_worker
Call Trace:
 dump_stack_lvl+0x57/0x7d
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds+0x69/0x80
 ? memcpy+0x39/0x60
 brcmf_fweh_event_worker+0xae1/0xc00
 ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x873/0x13e0
 ? lock_release+0x640/0x640
 ? pwq_dec_nr_in_flight+0x320/0x320
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x8b/0xd10
 ? __kthread_parkme+0xd9/0x1d0
 ? process_one_work+0x13e0/0x13e0
 kthread+0x379/0x450
 ? _raw_spin_unlock_irq+0x24/0x30
 ? set_kthread_struct+0x100/0x100
 ret_from_fork+0x1f/0x30
================================================================================
general protection fault, probably for non-canonical address 0xe5601c0020023fff: 0000 [#1] SMP KASAN
KASAN: maybe wild-memory-access in range [0x2b0100010011fff8-0x2b0100010011ffff]
CPU: 0 PID: 1898 Comm: kworker/0:2 Tainted: G           O      5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: events brcmf_fweh_event_worker
RIP: 0010:brcmf_fweh_call_event_handler.isra.0+0x42/0x100
Code: 89 f5 53 48 89 fb 48 83 ec 08 e8 79 0b 38 fe 48 85 ed 74 7e e8 6f 0b 38 fe 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 &lt;80&gt; 3c 02 00 0f 85 8b 00 00 00 4c 8b 7d 00 44 89 e0 48 ba 00 00 00
RSP: 0018:ffffc9000259fbd8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff888115d8cd50 RCX: 0000000000000000
RDX: 0560200020023fff RSI: ffffffff8304bc91 RDI: ffff888115d8cd50
RBP: 2b0100010011ffff R08: ffff888112340050 R09: ffffed1023549809
R10: ffff88811aa4c047 R11: ffffed1023549808 R12: 0000000000000045
R13: ffffc9000259fca0 R14: ffff888112340050 R15: ffff888112340000
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004053ccc0 CR3: 0000000112740000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 brcmf_fweh_event_worker+0x117/0xc00
 ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x873/0x13e0
 ? lock_release+0x640/0x640
 ? pwq_dec_nr_in_flight+0x320/0x320
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x8b/0xd10
 ? __kthread_parkme+0xd9/0x1d0
 ? process_one_work+0x13e0/0x13e0
 kthread+0x379/0x450
 ? _raw_spin_unlock_irq+0x24/0x30
 ? set_kthread_struct+0x100/0x100
 ret_from_fork+0x1f/0x30
Modules linked in: 88XXau(O) 88x2bu(O)
---[ end trace 41d302138f3ff55a ]---
RIP: 0010:brcmf_fweh_call_event_handler.isra.0+0x42/0x100
Code: 89 f5 53 48 89 fb 48 83 ec 08 e8 79 0b 38 fe 48 85 ed 74 7e e8 6f 0b 38 fe 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 &lt;80&gt; 3c 02 00 0f 85 8b 00 00 00 4c 8b 7d 00 44 89 e0 48 ba 00 00 00
RSP: 0018:ffffc9000259fbd8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff888115d8cd50 RCX: 0000000000000000
RDX: 0560200020023fff RSI: ffffffff8304bc91 RDI: ffff888115d8cd50
RBP: 2b0100010011ffff R08: ffff888112340050 R09: ffffed1023549809
R10: ffff88811aa4c047 R11: ffffed1023549808 R12: 0000000000000045
R13: ffffc9000259fca0 R14: ffff888112340050 R15: ffff888112340000
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004053ccc0 CR3: 0000000112740000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Kernel panic - not syncing: Fatal exception

Reported-by: Dokyung Song &lt;dokyungs@yonsei.ac.kr&gt;
Reported-by: Jisoo Jang &lt;jisoo.jang@yonsei.ac.kr&gt;
Reported-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Reviewed-by: Arend van Spriel &lt;aspriel@gmail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Dokyung Song &lt;dokyung.song@gmail.com&gt;
Signed-off-by: Kalle Valo &lt;kvalo@kernel.org&gt;
Link: https://lore.kernel.org/r/20221021061359.GA550858@laguna
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6788ba8aed4e28e90f72d68a9d794e34eac17295 upstream.

This patch fixes an intra-object buffer overflow in brcmfmac that occurs
when the device provides a 'bsscfgidx' equal to or greater than the
buffer size. The patch adds a check that leads to a safe failure if that
is the case.

This fixes CVE-2022-3628.

UBSAN: array-index-out-of-bounds in drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index 52 is out of range for type 'brcmf_if *[16]'
CPU: 0 PID: 1898 Comm: kworker/0:2 Tainted: G           O      5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: events brcmf_fweh_event_worker
Call Trace:
 dump_stack_lvl+0x57/0x7d
 ubsan_epilogue+0x5/0x40
 __ubsan_handle_out_of_bounds+0x69/0x80
 ? memcpy+0x39/0x60
 brcmf_fweh_event_worker+0xae1/0xc00
 ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x873/0x13e0
 ? lock_release+0x640/0x640
 ? pwq_dec_nr_in_flight+0x320/0x320
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x8b/0xd10
 ? __kthread_parkme+0xd9/0x1d0
 ? process_one_work+0x13e0/0x13e0
 kthread+0x379/0x450
 ? _raw_spin_unlock_irq+0x24/0x30
 ? set_kthread_struct+0x100/0x100
 ret_from_fork+0x1f/0x30
================================================================================
general protection fault, probably for non-canonical address 0xe5601c0020023fff: 0000 [#1] SMP KASAN
KASAN: maybe wild-memory-access in range [0x2b0100010011fff8-0x2b0100010011ffff]
CPU: 0 PID: 1898 Comm: kworker/0:2 Tainted: G           O      5.14.0+ #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: events brcmf_fweh_event_worker
RIP: 0010:brcmf_fweh_call_event_handler.isra.0+0x42/0x100
Code: 89 f5 53 48 89 fb 48 83 ec 08 e8 79 0b 38 fe 48 85 ed 74 7e e8 6f 0b 38 fe 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 &lt;80&gt; 3c 02 00 0f 85 8b 00 00 00 4c 8b 7d 00 44 89 e0 48 ba 00 00 00
RSP: 0018:ffffc9000259fbd8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff888115d8cd50 RCX: 0000000000000000
RDX: 0560200020023fff RSI: ffffffff8304bc91 RDI: ffff888115d8cd50
RBP: 2b0100010011ffff R08: ffff888112340050 R09: ffffed1023549809
R10: ffff88811aa4c047 R11: ffffed1023549808 R12: 0000000000000045
R13: ffffc9000259fca0 R14: ffff888112340050 R15: ffff888112340000
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004053ccc0 CR3: 0000000112740000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 brcmf_fweh_event_worker+0x117/0xc00
 ? brcmf_fweh_call_event_handler.isra.0+0x100/0x100
 ? rcu_read_lock_sched_held+0xa1/0xd0
 ? rcu_read_lock_bh_held+0xb0/0xb0
 ? lockdep_hardirqs_on_prepare+0x273/0x3e0
 process_one_work+0x873/0x13e0
 ? lock_release+0x640/0x640
 ? pwq_dec_nr_in_flight+0x320/0x320
 ? rwlock_bug.part.0+0x90/0x90
 worker_thread+0x8b/0xd10
 ? __kthread_parkme+0xd9/0x1d0
 ? process_one_work+0x13e0/0x13e0
 kthread+0x379/0x450
 ? _raw_spin_unlock_irq+0x24/0x30
 ? set_kthread_struct+0x100/0x100
 ret_from_fork+0x1f/0x30
Modules linked in: 88XXau(O) 88x2bu(O)
---[ end trace 41d302138f3ff55a ]---
RIP: 0010:brcmf_fweh_call_event_handler.isra.0+0x42/0x100
Code: 89 f5 53 48 89 fb 48 83 ec 08 e8 79 0b 38 fe 48 85 ed 74 7e e8 6f 0b 38 fe 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 &lt;80&gt; 3c 02 00 0f 85 8b 00 00 00 4c 8b 7d 00 44 89 e0 48 ba 00 00 00
RSP: 0018:ffffc9000259fbd8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff888115d8cd50 RCX: 0000000000000000
RDX: 0560200020023fff RSI: ffffffff8304bc91 RDI: ffff888115d8cd50
RBP: 2b0100010011ffff R08: ffff888112340050 R09: ffffed1023549809
R10: ffff88811aa4c047 R11: ffffed1023549808 R12: 0000000000000045
R13: ffffc9000259fca0 R14: ffff888112340050 R15: ffff888112340000
FS:  0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000004053ccc0 CR3: 0000000112740000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Kernel panic - not syncing: Fatal exception

Reported-by: Dokyung Song &lt;dokyungs@yonsei.ac.kr&gt;
Reported-by: Jisoo Jang &lt;jisoo.jang@yonsei.ac.kr&gt;
Reported-by: Minsuk Kang &lt;linuxlovemin@yonsei.ac.kr&gt;
Reviewed-by: Arend van Spriel &lt;aspriel@gmail.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Dokyung Song &lt;dokyung.song@gmail.com&gt;
Signed-off-by: Kalle Valo &lt;kvalo@kernel.org&gt;
Link: https://lore.kernel.org/r/20221021061359.GA550858@laguna
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>stmmac: dwmac-loongson: fix invalid mdio_node</title>
<updated>2022-11-10T17:15:31+00:00</updated>
<author>
<name>Liu Peibao</name>
<email>liupeibao@loongson.cn</email>
</author>
<published>2022-11-01T06:02:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de889774273ff2c4835fd99bc47c5b02eee58631'/>
<id>de889774273ff2c4835fd99bc47c5b02eee58631</id>
<content type='text'>
[ Upstream commit 2ae34111fe4eebb69986f6490015b57c88804373 ]

In current code "plat-&gt;mdio_node" is always NULL, the mdio
support is lost as there is no "mdio_bus_data". The original
driver could work as the "mdio" variable is never set to
false, which is described in commit &lt;b0e03950dd71&gt; ("stmmac:
dwmac-loongson: fix uninitialized variable ......"). And
after this commit merged, the "mdio" variable is always
false, causing the mdio supoort logic lost.

Fixes: 30bba69d7db4 ("stmmac: pci: Add dwmac support for Loongson")
Signed-off-by: Liu Peibao &lt;liupeibao@loongson.cn&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20221101060218.16453-1-liupeibao@loongson.cn
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2ae34111fe4eebb69986f6490015b57c88804373 ]

In current code "plat-&gt;mdio_node" is always NULL, the mdio
support is lost as there is no "mdio_bus_data". The original
driver could work as the "mdio" variable is never set to
false, which is described in commit &lt;b0e03950dd71&gt; ("stmmac:
dwmac-loongson: fix uninitialized variable ......"). And
after this commit merged, the "mdio" variable is always
false, causing the mdio supoort logic lost.

Fixes: 30bba69d7db4 ("stmmac: pci: Add dwmac support for Loongson")
Signed-off-by: Liu Peibao &lt;liupeibao@loongson.cn&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20221101060218.16453-1-liupeibao@loongson.cn
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ibmvnic: Free rwi on reset success</title>
<updated>2022-11-10T17:15:31+00:00</updated>
<author>
<name>Nick Child</name>
<email>nnac123@linux.ibm.com</email>
</author>
<published>2022-10-31T15:06:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=535b78739ae75f257c894a05b1afa86ad9a3669e'/>
<id>535b78739ae75f257c894a05b1afa86ad9a3669e</id>
<content type='text'>
[ Upstream commit d6dd2fe71153f0ff748bf188bd4af076fe09a0a6 ]

Free the rwi structure in the event that the last rwi in the list
processed successfully. The logic in commit 4f408e1fa6e1 ("ibmvnic:
retry reset if there are no other resets") introduces an issue that
results in a 32 byte memory leak whenever the last rwi in the list
gets processed.

Fixes: 4f408e1fa6e1 ("ibmvnic: retry reset if there are no other resets")
Signed-off-by: Nick Child &lt;nnac123@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20221031150642.13356-1-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d6dd2fe71153f0ff748bf188bd4af076fe09a0a6 ]

Free the rwi structure in the event that the last rwi in the list
processed successfully. The logic in commit 4f408e1fa6e1 ("ibmvnic:
retry reset if there are no other resets") introduces an issue that
results in a 32 byte memory leak whenever the last rwi in the list
gets processed.

Fixes: 4f408e1fa6e1 ("ibmvnic: retry reset if there are no other resets")
Signed-off-by: Nick Child &lt;nnac123@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20221031150642.13356-1-nnac123@linux.ibm.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: mdio: fix undefined behavior in bit shift for __mdiobus_register</title>
<updated>2022-11-10T17:15:30+00:00</updated>
<author>
<name>Gaosheng Cui</name>
<email>cuigaosheng1@huawei.com</email>
</author>
<published>2022-10-31T13:26:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=985a88bf0b27193522bba7856b1763f428cef19d'/>
<id>985a88bf0b27193522bba7856b1763f428cef19d</id>
<content type='text'>
[ Upstream commit 40e4eb324c59e11fcb927aa46742d28aba6ecb8a ]

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in drivers/net/phy/mdio_bus.c:586:27
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 &lt;TASK&gt;
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 __mdiobus_register+0x49d/0x4e0
 fixed_mdio_bus_init+0xd8/0x12d
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 &lt;/TASK&gt;

Fixes: 4fd5f812c23c ("phylib: allow incremental scanning of an mii bus")
Signed-off-by: Gaosheng Cui &lt;cuigaosheng1@huawei.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20221031132645.168421-1-cuigaosheng1@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 40e4eb324c59e11fcb927aa46742d28aba6ecb8a ]

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in drivers/net/phy/mdio_bus.c:586:27
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 &lt;TASK&gt;
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 __mdiobus_register+0x49d/0x4e0
 fixed_mdio_bus_init+0xd8/0x12d
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 &lt;/TASK&gt;

Fixes: 4fd5f812c23c ("phylib: allow incremental scanning of an mii bus")
Signed-off-by: Gaosheng Cui &lt;cuigaosheng1@huawei.com&gt;
Reviewed-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Link: https://lore.kernel.org/r/20221031132645.168421-1-cuigaosheng1@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: tun: fix bugs for oversize packet when napi frags enabled</title>
<updated>2022-11-10T17:15:28+00:00</updated>
<author>
<name>Ziyang Xuan</name>
<email>william.xuanziyang@huawei.com</email>
</author>
<published>2022-10-29T09:41:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dcc79cf735b8ec4bedaa82c53bed8c62721c042b'/>
<id>dcc79cf735b8ec4bedaa82c53bed8c62721c042b</id>
<content type='text'>
[ Upstream commit 363a5328f4b0517e59572118ccfb7c626d81dca9 ]

Recently, we got two syzkaller problems because of oversize packet
when napi frags enabled.

One of the problems is because the first seg size of the iov_iter
from user space is very big, it is 2147479538 which is bigger than
the threshold value for bail out early in __alloc_pages(). And
skb-&gt;pfmemalloc is true, __kmalloc_reserve() would use pfmemalloc
reserves without __GFP_NOWARN flag. Thus we got a warning as following:

========================================================
WARNING: CPU: 1 PID: 17965 at mm/page_alloc.c:5295 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
...
Call trace:
 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
 __alloc_pages_node include/linux/gfp.h:550 [inline]
 alloc_pages_node include/linux/gfp.h:564 [inline]
 kmalloc_large_node+0x94/0x350 mm/slub.c:4038
 __kmalloc_node_track_caller+0x620/0x8e4 mm/slub.c:4545
 __kmalloc_reserve.constprop.0+0x1e4/0x2b0 net/core/skbuff.c:151
 pskb_expand_head+0x130/0x8b0 net/core/skbuff.c:1654
 __skb_grow include/linux/skbuff.h:2779 [inline]
 tun_napi_alloc_frags+0x144/0x610 drivers/net/tun.c:1477
 tun_get_user+0x31c/0x2010 drivers/net/tun.c:1835
 tun_chr_write_iter+0x98/0x100 drivers/net/tun.c:2036

The other problem is because odd IPv6 packets without NEXTHDR_NONE
extension header and have big packet length, it is 2127925 which is
bigger than ETH_MAX_MTU(65535). After ipv6_gso_pull_exthdrs() in
ipv6_gro_receive(), network_header offset and transport_header offset
are all bigger than U16_MAX. That would trigger skb-&gt;network_header
and skb-&gt;transport_header overflow error, because they are all '__u16'
type. Eventually, it would affect the value for __skb_push(skb, value),
and make it be a big value. After __skb_push() in ipv6_gro_receive(),
skb-&gt;data would less than skb-&gt;head, an out of bounds memory bug occurred.
That would trigger the problem as following:

==================================================================
BUG: KASAN: use-after-free in eth_type_trans+0x100/0x260
...
Call trace:
 dump_backtrace+0xd8/0x130
 show_stack+0x1c/0x50
 dump_stack_lvl+0x64/0x7c
 print_address_description.constprop.0+0xbc/0x2e8
 print_report+0x100/0x1e4
 kasan_report+0x80/0x120
 __asan_load8+0x78/0xa0
 eth_type_trans+0x100/0x260
 napi_gro_frags+0x164/0x550
 tun_get_user+0xda4/0x1270
 tun_chr_write_iter+0x74/0x130
 do_iter_readv_writev+0x130/0x1ec
 do_iter_write+0xbc/0x1e0
 vfs_writev+0x13c/0x26c

To fix the problems, restrict the packet size less than
(ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN) which has considered reserved
skb space in napi_alloc_skb() because transport_header is an offset from
skb-&gt;head. Add len check in tun_napi_alloc_frags() simply.

Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20221029094101.1653855-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 363a5328f4b0517e59572118ccfb7c626d81dca9 ]

Recently, we got two syzkaller problems because of oversize packet
when napi frags enabled.

One of the problems is because the first seg size of the iov_iter
from user space is very big, it is 2147479538 which is bigger than
the threshold value for bail out early in __alloc_pages(). And
skb-&gt;pfmemalloc is true, __kmalloc_reserve() would use pfmemalloc
reserves without __GFP_NOWARN flag. Thus we got a warning as following:

========================================================
WARNING: CPU: 1 PID: 17965 at mm/page_alloc.c:5295 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
...
Call trace:
 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
 __alloc_pages_node include/linux/gfp.h:550 [inline]
 alloc_pages_node include/linux/gfp.h:564 [inline]
 kmalloc_large_node+0x94/0x350 mm/slub.c:4038
 __kmalloc_node_track_caller+0x620/0x8e4 mm/slub.c:4545
 __kmalloc_reserve.constprop.0+0x1e4/0x2b0 net/core/skbuff.c:151
 pskb_expand_head+0x130/0x8b0 net/core/skbuff.c:1654
 __skb_grow include/linux/skbuff.h:2779 [inline]
 tun_napi_alloc_frags+0x144/0x610 drivers/net/tun.c:1477
 tun_get_user+0x31c/0x2010 drivers/net/tun.c:1835
 tun_chr_write_iter+0x98/0x100 drivers/net/tun.c:2036

The other problem is because odd IPv6 packets without NEXTHDR_NONE
extension header and have big packet length, it is 2127925 which is
bigger than ETH_MAX_MTU(65535). After ipv6_gso_pull_exthdrs() in
ipv6_gro_receive(), network_header offset and transport_header offset
are all bigger than U16_MAX. That would trigger skb-&gt;network_header
and skb-&gt;transport_header overflow error, because they are all '__u16'
type. Eventually, it would affect the value for __skb_push(skb, value),
and make it be a big value. After __skb_push() in ipv6_gro_receive(),
skb-&gt;data would less than skb-&gt;head, an out of bounds memory bug occurred.
That would trigger the problem as following:

==================================================================
BUG: KASAN: use-after-free in eth_type_trans+0x100/0x260
...
Call trace:
 dump_backtrace+0xd8/0x130
 show_stack+0x1c/0x50
 dump_stack_lvl+0x64/0x7c
 print_address_description.constprop.0+0xbc/0x2e8
 print_report+0x100/0x1e4
 kasan_report+0x80/0x120
 __asan_load8+0x78/0xa0
 eth_type_trans+0x100/0x260
 napi_gro_frags+0x164/0x550
 tun_get_user+0xda4/0x1270
 tun_chr_write_iter+0x74/0x130
 do_iter_readv_writev+0x130/0x1ec
 do_iter_write+0xbc/0x1e0
 vfs_writev+0x13c/0x26c

To fix the problems, restrict the packet size less than
(ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN) which has considered reserved
skb space in napi_alloc_skb() because transport_header is an offset from
skb-&gt;head. Add len check in tun_napi_alloc_frags() simply.

Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20221029094101.1653855-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: fec: fix improper use of NETDEV_TX_BUSY</title>
<updated>2022-11-10T17:15:28+00:00</updated>
<author>
<name>Zhang Changzhong</name>
<email>zhangchangzhong@huawei.com</email>
</author>
<published>2022-10-28T02:09:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dede9ba02705e84ff5aae0ebffbad5a37ea24a54'/>
<id>dede9ba02705e84ff5aae0ebffbad5a37ea24a54</id>
<content type='text'>
[ Upstream commit 06a4df5863f73af193a4ff7abf7cb04058584f06 ]

The ndo_start_xmit() method must not free skb when returning
NETDEV_TX_BUSY, since caller is going to requeue freed skb.

Fix it by returning NETDEV_TX_OK in case of dma_map_single() fails.

Fixes: 79f339125ea3 ("net: fec: Add software TSO support")
Signed-off-by: Zhang Changzhong &lt;zhangchangzhong@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 06a4df5863f73af193a4ff7abf7cb04058584f06 ]

The ndo_start_xmit() method must not free skb when returning
NETDEV_TX_BUSY, since caller is going to requeue freed skb.

Fix it by returning NETDEV_TX_OK in case of dma_map_single() fails.

Fixes: 79f339125ea3 ("net: fec: Add software TSO support")
Signed-off-by: Zhang Changzhong &lt;zhangchangzhong@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: dsa: Fix possible memory leaks in dsa_loop_init()</title>
<updated>2022-11-10T17:15:27+00:00</updated>
<author>
<name>Chen Zhongjin</name>
<email>chenzhongjin@huawei.com</email>
</author>
<published>2022-10-26T02:03:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9f555b1584fc2d5d16ee3c4d9438e93ac7c502c7'/>
<id>9f555b1584fc2d5d16ee3c4d9438e93ac7c502c7</id>
<content type='text'>
[ Upstream commit 633efc8b3dc96f56f5a57f2a49764853a2fa3f50 ]

kmemleak reported memory leaks in dsa_loop_init():

kmemleak: 12 new suspected memory leaks

unreferenced object 0xffff8880138ce000 (size 2048):
  comm "modprobe", pid 390, jiffies 4295040478 (age 238.976s)
  backtrace:
    [&lt;000000006a94f1d5&gt;] kmalloc_trace+0x26/0x60
    [&lt;00000000a9c44622&gt;] phy_device_create+0x5d/0x970
    [&lt;00000000d0ee2afc&gt;] get_phy_device+0xf3/0x2b0
    [&lt;00000000dca0c71f&gt;] __fixed_phy_register.part.0+0x92/0x4e0
    [&lt;000000008a834798&gt;] fixed_phy_register+0x84/0xb0
    [&lt;0000000055223fcb&gt;] dsa_loop_init+0xa9/0x116 [dsa_loop]
    ...

There are two reasons for memleak in dsa_loop_init().

First, fixed_phy_register() create and register phy_device:

fixed_phy_register()
  get_phy_device()
    phy_device_create() # freed by phy_device_free()
  phy_device_register() # freed by phy_device_remove()

But fixed_phy_unregister() only calls phy_device_remove().
So the memory allocated in phy_device_create() is leaked.

Second, when mdio_driver_register() fail in dsa_loop_init(),
it just returns and there is no cleanup for phydevs.

Fix the problems by catching the error of mdio_driver_register()
in dsa_loop_init(), then calling both fixed_phy_unregister() and
phy_device_free() to release phydevs.
Also add a function for phydevs cleanup to avoid duplacate.

Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 633efc8b3dc96f56f5a57f2a49764853a2fa3f50 ]

kmemleak reported memory leaks in dsa_loop_init():

kmemleak: 12 new suspected memory leaks

unreferenced object 0xffff8880138ce000 (size 2048):
  comm "modprobe", pid 390, jiffies 4295040478 (age 238.976s)
  backtrace:
    [&lt;000000006a94f1d5&gt;] kmalloc_trace+0x26/0x60
    [&lt;00000000a9c44622&gt;] phy_device_create+0x5d/0x970
    [&lt;00000000d0ee2afc&gt;] get_phy_device+0xf3/0x2b0
    [&lt;00000000dca0c71f&gt;] __fixed_phy_register.part.0+0x92/0x4e0
    [&lt;000000008a834798&gt;] fixed_phy_register+0x84/0xb0
    [&lt;0000000055223fcb&gt;] dsa_loop_init+0xa9/0x116 [dsa_loop]
    ...

There are two reasons for memleak in dsa_loop_init().

First, fixed_phy_register() create and register phy_device:

fixed_phy_register()
  get_phy_device()
    phy_device_create() # freed by phy_device_free()
  phy_device_register() # freed by phy_device_remove()

But fixed_phy_unregister() only calls phy_device_remove().
So the memory allocated in phy_device_create() is leaked.

Second, when mdio_driver_register() fail in dsa_loop_init(),
it just returns and there is no cleanup for phydevs.

Fix the problems by catching the error of mdio_driver_register()
in dsa_loop_init(), then calling both fixed_phy_unregister() and
phy_device_free() to release phydevs.
Also add a function for phydevs cleanup to avoid duplacate.

Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: rcar_canfd: rcar_canfd_handle_global_receive(): fix IRQ storm on global FIFO receive</title>
<updated>2022-11-03T14:59:20+00:00</updated>
<author>
<name>Biju Das</name>
<email>biju.das.jz@bp.renesas.com</email>
</author>
<published>2022-10-25T15:56:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0753069d4431e678565a545b53137d3977c8124c'/>
<id>0753069d4431e678565a545b53137d3977c8124c</id>
<content type='text'>
commit 702de2c21eed04c67cefaaedc248ef16e5f6b293 upstream.

We are seeing an IRQ storm on the global receive IRQ line under heavy
CAN bus load conditions with both CAN channels enabled.

Conditions:

The global receive IRQ line is shared between can0 and can1, either of
the channels can trigger interrupt while the other channel's IRQ line
is disabled (RFIE).

When global a receive IRQ interrupt occurs, we mask the interrupt in
the IRQ handler. Clearing and unmasking of the interrupt is happening
in rx_poll(). There is a race condition where rx_poll() unmasks the
interrupt, but the next IRQ handler does not mask the IRQ due to
NAPIF_STATE_MISSED flag (e.g.: can0 RX FIFO interrupt is disabled and
can1 is triggering RX interrupt, the delay in rx_poll() processing
results in setting NAPIF_STATE_MISSED flag) leading to an IRQ storm.

This patch fixes the issue by checking IRQ active and enabled before
handling the IRQ on a particular channel.

Fixes: dd3bd23eb438 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver")
Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/all/20221025155657.1426948-2-biju.das.jz@bp.renesas.com
Cc: stable@vger.kernel.org
[mkl: adjust commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
[biju: removed gpriv from RCANFD_RFCC_RFIE macro]
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 702de2c21eed04c67cefaaedc248ef16e5f6b293 upstream.

We are seeing an IRQ storm on the global receive IRQ line under heavy
CAN bus load conditions with both CAN channels enabled.

Conditions:

The global receive IRQ line is shared between can0 and can1, either of
the channels can trigger interrupt while the other channel's IRQ line
is disabled (RFIE).

When global a receive IRQ interrupt occurs, we mask the interrupt in
the IRQ handler. Clearing and unmasking of the interrupt is happening
in rx_poll(). There is a race condition where rx_poll() unmasks the
interrupt, but the next IRQ handler does not mask the IRQ due to
NAPIF_STATE_MISSED flag (e.g.: can0 RX FIFO interrupt is disabled and
can1 is triggering RX interrupt, the delay in rx_poll() processing
results in setting NAPIF_STATE_MISSED flag) leading to an IRQ storm.

This patch fixes the issue by checking IRQ active and enabled before
handling the IRQ on a particular channel.

Fixes: dd3bd23eb438 ("can: rcar_canfd: Add Renesas R-Car CAN FD driver")
Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/all/20221025155657.1426948-2-biju.das.jz@bp.renesas.com
Cc: stable@vger.kernel.org
[mkl: adjust commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
[biju: removed gpriv from RCANFD_RFCC_RFIE macro]
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: rcar_canfd: fix channel specific IRQ handling for RZ/G2L</title>
<updated>2022-11-03T14:59:20+00:00</updated>
<author>
<name>Biju Das</name>
<email>biju.das.jz@bp.renesas.com</email>
</author>
<published>2022-10-25T15:56:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17ff99e2240c6f35fd3981383fd9de991a266ff0'/>
<id>17ff99e2240c6f35fd3981383fd9de991a266ff0</id>
<content type='text'>
commit d887087c896881715c1a82f1d4f71fbfe5344ffd upstream.

RZ/G2L has separate channel specific IRQs for transmit and error
interrupts. But the IRQ handler processes both channels, even if there
no interrupt occurred on one of the channels.

This patch fixes the issue by passing a channel specific context
parameter instead of global one for the IRQ register and the IRQ
handler, it just handles the channel which is triggered the interrupt.

Fixes: 76e9353a80e9 ("can: rcar_canfd: Add support for RZ/G2L family")
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/all/20221025155657.1426948-3-biju.das.jz@bp.renesas.com
Cc: stable@vger.kernel.org
[mkl: adjust commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
[biju: fixed the conflicts manually]
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d887087c896881715c1a82f1d4f71fbfe5344ffd upstream.

RZ/G2L has separate channel specific IRQs for transmit and error
interrupts. But the IRQ handler processes both channels, even if there
no interrupt occurred on one of the channels.

This patch fixes the issue by passing a channel specific context
parameter instead of global one for the IRQ register and the IRQ
handler, it just handles the channel which is triggered the interrupt.

Fixes: 76e9353a80e9 ("can: rcar_canfd: Add support for RZ/G2L family")
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Link: https://lore.kernel.org/all/20221025155657.1426948-3-biju.das.jz@bp.renesas.com
Cc: stable@vger.kernel.org
[mkl: adjust commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
[biju: fixed the conflicts manually]
Signed-off-by: Biju Das &lt;biju.das.jz@bp.renesas.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: enetc: survive memory pressure without crashing</title>
<updated>2022-11-03T14:59:19+00:00</updated>
<author>
<name>Vladimir Oltean</name>
<email>vladimir.oltean@nxp.com</email>
</author>
<published>2022-10-27T18:29:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5397ea6a08a530685e715d91b5cca09ff7cda166'/>
<id>5397ea6a08a530685e715d91b5cca09ff7cda166</id>
<content type='text'>
[ Upstream commit 84ce1ca3fe9e1249bf21176ff162200f1c4e5ed1 ]

Under memory pressure, enetc_refill_rx_ring() may fail, and when called
during the enetc_open() -&gt; enetc_setup_rxbdr() procedure, this is not
checked for.

An extreme case of memory pressure will result in exactly zero buffers
being allocated for the RX ring, and in such a case it is expected that
hardware drops all RX packets due to lack of buffers.

This does not happen, because the reset-default value of the consumer
and produces index is 0, and this makes the ENETC think that all buffers
have been initialized and that it owns them (when in reality none were).

The hardware guide explains this best:

| Configure the receive ring producer index register RBaPIR with a value
| of 0. The producer index is initially configured by software but owned
| by hardware after the ring has been enabled. Hardware increments the
| index when a frame is received which may consume one or more BDs.
| Hardware is not allowed to increment the producer index to match the
| consumer index since it is used to indicate an empty condition. The ring
| can hold at most RBLENR[LENGTH]-1 received BDs.
|
| Configure the receive ring consumer index register RBaCIR. The
| consumer index is owned by software and updated during operation of the
| of the BD ring by software, to indicate that any receive data occupied
| in the BD has been processed and it has been prepared for new data.
| - If consumer index and producer index are initialized to the same
|   value, it indicates that all BDs in the ring have been prepared and
|   hardware owns all of the entries.
| - If consumer index is initialized to producer index plus N, it would
|   indicate N BDs have been prepared. Note that hardware cannot start if
|   only a single buffer is prepared due to the restrictions described in
|   (2).
| - Software may write consumer index to match producer index anytime
|   while the ring is operational to indicate all received BDs prior have
|   been processed and new BDs prepared for hardware.

Normally, the value of rx_ring-&gt;rcir (consumer index) is brought in sync
with the rx_ring-&gt;next_to_use software index, but this only happens if
page allocation ever succeeded.

When PI==CI==0, the hardware appears to receive frames and write them to
DMA address 0x0 (?!), then set the READY bit in the BD.

The enetc_clean_rx_ring() function (and its XDP derivative) is naturally
not prepared to handle such a condition. It will attempt to process
those frames using the rx_swbd structure associated with index i of the
RX ring, but that structure is not fully initialized (enetc_new_page()
does all of that). So what happens next is undefined behavior.

To operate using no buffer, we must initialize the CI to PI + 1, which
will block the hardware from advancing the CI any further, and drop
everything.

The issue was seen while adding support for zero-copy AF_XDP sockets,
where buffer memory comes from user space, which can even decide to
supply no buffers at all (example: "xdpsock --txonly"). However, the bug
is present also with the network stack code, even though it would take a
very determined person to trigger a page allocation failure at the
perfect time (a series of ifup/ifdown under memory pressure should
eventually reproduce it given enough retries).

Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Claudiu Manoil &lt;claudiu.manoil@nxp.com&gt;
Link: https://lore.kernel.org/r/20221027182925.3256653-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
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[ Upstream commit 84ce1ca3fe9e1249bf21176ff162200f1c4e5ed1 ]

Under memory pressure, enetc_refill_rx_ring() may fail, and when called
during the enetc_open() -&gt; enetc_setup_rxbdr() procedure, this is not
checked for.

An extreme case of memory pressure will result in exactly zero buffers
being allocated for the RX ring, and in such a case it is expected that
hardware drops all RX packets due to lack of buffers.

This does not happen, because the reset-default value of the consumer
and produces index is 0, and this makes the ENETC think that all buffers
have been initialized and that it owns them (when in reality none were).

The hardware guide explains this best:

| Configure the receive ring producer index register RBaPIR with a value
| of 0. The producer index is initially configured by software but owned
| by hardware after the ring has been enabled. Hardware increments the
| index when a frame is received which may consume one or more BDs.
| Hardware is not allowed to increment the producer index to match the
| consumer index since it is used to indicate an empty condition. The ring
| can hold at most RBLENR[LENGTH]-1 received BDs.
|
| Configure the receive ring consumer index register RBaCIR. The
| consumer index is owned by software and updated during operation of the
| of the BD ring by software, to indicate that any receive data occupied
| in the BD has been processed and it has been prepared for new data.
| - If consumer index and producer index are initialized to the same
|   value, it indicates that all BDs in the ring have been prepared and
|   hardware owns all of the entries.
| - If consumer index is initialized to producer index plus N, it would
|   indicate N BDs have been prepared. Note that hardware cannot start if
|   only a single buffer is prepared due to the restrictions described in
|   (2).
| - Software may write consumer index to match producer index anytime
|   while the ring is operational to indicate all received BDs prior have
|   been processed and new BDs prepared for hardware.

Normally, the value of rx_ring-&gt;rcir (consumer index) is brought in sync
with the rx_ring-&gt;next_to_use software index, but this only happens if
page allocation ever succeeded.

When PI==CI==0, the hardware appears to receive frames and write them to
DMA address 0x0 (?!), then set the READY bit in the BD.

The enetc_clean_rx_ring() function (and its XDP derivative) is naturally
not prepared to handle such a condition. It will attempt to process
those frames using the rx_swbd structure associated with index i of the
RX ring, but that structure is not fully initialized (enetc_new_page()
does all of that). So what happens next is undefined behavior.

To operate using no buffer, we must initialize the CI to PI + 1, which
will block the hardware from advancing the CI any further, and drop
everything.

The issue was seen while adding support for zero-copy AF_XDP sockets,
where buffer memory comes from user space, which can even decide to
supply no buffers at all (example: "xdpsock --txonly"). However, the bug
is present also with the network stack code, even though it would take a
very determined person to trigger a page allocation failure at the
perfect time (a series of ifup/ifdown under memory pressure should
eventually reproduce it given enough retries).

Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Signed-off-by: Vladimir Oltean &lt;vladimir.oltean@nxp.com&gt;
Reviewed-by: Claudiu Manoil &lt;claudiu.manoil@nxp.com&gt;
Link: https://lore.kernel.org/r/20221027182925.3256653-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
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