<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git, branch v6.6.42</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v6.6.42</id>
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<updated>2024-07-25T07:50:58Z</updated>
<entry>
<title>Linux 6.6.42</title>
<updated>2024-07-25T07:50:58Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2024-07-25T07:50:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=31cf7ebee80af912aff36445ba7bd057e2146231'/>
<id>urn:sha1:31cf7ebee80af912aff36445ba7bd057e2146231</id>
<content type='text'>
Link: https://lore.kernel.org/r/20240723180404.759900207@linuxfoundation.org
Tested-by: Florian Fainelli &lt;florian.fainelli@broadcom.com&gt;
Tested-by: Jon Hunter &lt;jonathanh@nvidia.com&gt;
Tested-by: Harshit Mogalapalli &lt;harshit.m.mogalapalli@oracle.com&gt;
Tested-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Tested-by: Mark Brown &lt;broonie@kernel.org&gt;
Tested-by: Takeshi Ogasawara &lt;takeshi.ogasawara@futuring-girl.com&gt;
Tested-by: Peter Schneider &lt;pschneider1968@googlemail.com&gt;
Tested-by: kernelci.org bot &lt;bot@kernelci.org&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Ron Economos &lt;re@w6rz.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()</title>
<updated>2024-07-25T07:50:58Z</updated>
<author>
<name>Baokun Li</name>
<email>libaokun1@huawei.com</email>
</author>
<published>2024-07-19T13:40:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9e67589a4a7b7e5660b524d1d5fe61242bcbcc11'/>
<id>urn:sha1:9e67589a4a7b7e5660b524d1d5fe61242bcbcc11</id>
<content type='text'>
[ Upstream commit 5d8f805789072ea7fd39504694b7bd17e5f751c4 ]

We got the following issue in our fault injection stress test:

==================================================================
BUG: KASAN: slab-use-after-free in cachefiles_withdraw_cookie+0x4d9/0x600
Read of size 8 at addr ffff888118efc000 by task kworker/u78:0/109

CPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566
Call Trace:
 &lt;TASK&gt;
 kasan_report+0x93/0xc0
 cachefiles_withdraw_cookie+0x4d9/0x600
 fscache_cookie_state_machine+0x5c8/0x1230
 fscache_cookie_worker+0x91/0x1c0
 process_one_work+0x7fa/0x1800
 [...]

Allocated by task 117:
 kmalloc_trace+0x1b3/0x3c0
 cachefiles_acquire_volume+0xf3/0x9c0
 fscache_create_volume_work+0x97/0x150
 process_one_work+0x7fa/0x1800
 [...]

Freed by task 120301:
 kfree+0xf1/0x2c0
 cachefiles_withdraw_cache+0x3fa/0x920
 cachefiles_put_unbind_pincount+0x1f6/0x250
 cachefiles_daemon_release+0x13b/0x290
 __fput+0x204/0xa00
 task_work_run+0x139/0x230
 do_exit+0x87a/0x29b0
 [...]
==================================================================

Following is the process that triggers the issue:

           p1                |             p2
------------------------------------------------------------
                              fscache_begin_lookup
                               fscache_begin_volume_access
                                fscache_cache_is_live(fscache_cache)
cachefiles_daemon_release
 cachefiles_put_unbind_pincount
  cachefiles_daemon_unbind
   cachefiles_withdraw_cache
    fscache_withdraw_cache
     fscache_set_cache_state(cache, FSCACHE_CACHE_IS_WITHDRAWN);
    cachefiles_withdraw_objects(cache)
    fscache_wait_for_objects(fscache)
      atomic_read(&amp;fscache_cache-&gt;object_count) == 0
                              fscache_perform_lookup
                               cachefiles_lookup_cookie
                                cachefiles_alloc_object
                                 refcount_set(&amp;object-&gt;ref, 1);
                                 object-&gt;volume = volume
                                 fscache_count_object(vcookie-&gt;cache);
                                  atomic_inc(&amp;fscache_cache-&gt;object_count)
    cachefiles_withdraw_volumes
     cachefiles_withdraw_volume
      fscache_withdraw_volume
      __cachefiles_free_volume
       kfree(cachefiles_volume)
                              fscache_cookie_state_machine
                               cachefiles_withdraw_cookie
                                cache = object-&gt;volume-&gt;cache;
                                // cachefiles_volume UAF !!!

After setting FSCACHE_CACHE_IS_WITHDRAWN, wait for all the cookie lookups
to complete first, and then wait for fscache_cache-&gt;object_count == 0 to
avoid the cookie exiting after the volume has been freed and triggering
the above issue. Therefore call fscache_withdraw_volume() before calling
cachefiles_withdraw_objects().

This way, after setting FSCACHE_CACHE_IS_WITHDRAWN, only the following two
cases will occur:
1) fscache_begin_lookup fails in fscache_begin_volume_access().
2) fscache_withdraw_volume() will ensure that fscache_count_object() has
   been executed before calling fscache_wait_for_objects().

Fixes: fe2140e2f57f ("cachefiles: Implement volume support")
Suggested-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240628062930.2467993-4-libaokun@huaweicloud.com
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>cachefiles: fix slab-use-after-free in fscache_withdraw_volume()</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Baokun Li</name>
<email>libaokun1@huawei.com</email>
</author>
<published>2024-07-19T13:40:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9dd7f5663899ea13a6a73216106d9c13c37453e3'/>
<id>urn:sha1:9dd7f5663899ea13a6a73216106d9c13c37453e3</id>
<content type='text'>
[ Upstream commit 522018a0de6b6fcce60c04f86dfc5f0e4b6a1b36 ]

We got the following issue in our fault injection stress test:

==================================================================
BUG: KASAN: slab-use-after-free in fscache_withdraw_volume+0x2e1/0x370
Read of size 4 at addr ffff88810680be08 by task ondemand-04-dae/5798

CPU: 0 PID: 5798 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #565
Call Trace:
 kasan_check_range+0xf6/0x1b0
 fscache_withdraw_volume+0x2e1/0x370
 cachefiles_withdraw_volume+0x31/0x50
 cachefiles_withdraw_cache+0x3ad/0x900
 cachefiles_put_unbind_pincount+0x1f6/0x250
 cachefiles_daemon_release+0x13b/0x290
 __fput+0x204/0xa00
 task_work_run+0x139/0x230

Allocated by task 5820:
 __kmalloc+0x1df/0x4b0
 fscache_alloc_volume+0x70/0x600
 __fscache_acquire_volume+0x1c/0x610
 erofs_fscache_register_volume+0x96/0x1a0
 erofs_fscache_register_fs+0x49a/0x690
 erofs_fc_fill_super+0x6c0/0xcc0
 vfs_get_super+0xa9/0x140
 vfs_get_tree+0x8e/0x300
 do_new_mount+0x28c/0x580
 [...]

Freed by task 5820:
 kfree+0xf1/0x2c0
 fscache_put_volume.part.0+0x5cb/0x9e0
 erofs_fscache_unregister_fs+0x157/0x1b0
 erofs_kill_sb+0xd9/0x1c0
 deactivate_locked_super+0xa3/0x100
 vfs_get_super+0x105/0x140
 vfs_get_tree+0x8e/0x300
 do_new_mount+0x28c/0x580
 [...]
==================================================================

Following is the process that triggers the issue:

        mount failed         |         daemon exit
------------------------------------------------------------
 deactivate_locked_super        cachefiles_daemon_release
  erofs_kill_sb
   erofs_fscache_unregister_fs
    fscache_relinquish_volume
     __fscache_relinquish_volume
      fscache_put_volume(fscache_volume, fscache_volume_put_relinquish)
       zero = __refcount_dec_and_test(&amp;fscache_volume-&gt;ref, &amp;ref);
                                 cachefiles_put_unbind_pincount
                                  cachefiles_daemon_unbind
                                   cachefiles_withdraw_cache
                                    cachefiles_withdraw_volumes
                                     list_del_init(&amp;volume-&gt;cache_link)
       fscache_free_volume(fscache_volume)
        cache-&gt;ops-&gt;free_volume
         cachefiles_free_volume
          list_del_init(&amp;cachefiles_volume-&gt;cache_link);
        kfree(fscache_volume)
                                     cachefiles_withdraw_volume
                                      fscache_withdraw_volume
                                       fscache_volume-&gt;n_accesses
                                       // fscache_volume UAF !!!

The fscache_volume in cache-&gt;volumes must not have been freed yet, but its
reference count may be 0. So use the new fscache_try_get_volume() helper
function try to get its reference count.

If the reference count of fscache_volume is 0, fscache_put_volume() is
freeing it, so wait for it to be removed from cache-&gt;volumes.

If its reference count is not 0, call cachefiles_withdraw_volume() with
reference count protection to avoid the above issue.

Fixes: fe2140e2f57f ("cachefiles: Implement volume support")
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240628062930.2467993-3-libaokun@huaweicloud.com
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>netfs, fscache: export fscache_put_volume() and add fscache_try_get_volume()</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Baokun Li</name>
<email>libaokun1@huawei.com</email>
</author>
<published>2024-07-19T13:40:02Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5c5a577a2cc62969450650a076be7183339c0857'/>
<id>urn:sha1:5c5a577a2cc62969450650a076be7183339c0857</id>
<content type='text'>
[ Upstream commit 85b08b31a22b481ec6528130daf94eee4452e23f ]

Export fscache_put_volume() and add fscache_try_get_volume()
helper function to allow cachefiles to get/put fscache_volume
via linux/fscache-cache.h.

Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240628062930.2467993-2-libaokun@huaweicloud.com
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Stable-dep-of: 522018a0de6b ("cachefiles: fix slab-use-after-free in fscache_withdraw_volume()")
Stable-dep-of: 5d8f80578907 ("cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()")
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>wifi: iwlwifi: mvm: don't wake up rx_sync_waitq upon RFKILL</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Emmanuel Grumbach</name>
<email>emmanuel.grumbach@intel.com</email>
</author>
<published>2024-07-03T03:43:16Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=6f1fc7fea4b21bc13cc981224bd8bf3d3bfc0d68'/>
<id>urn:sha1:6f1fc7fea4b21bc13cc981224bd8bf3d3bfc0d68</id>
<content type='text'>
commit e715c9302b1c6fae990b9898a80fac855549d1f0 upstream.

Since we now want to sync the queues even when we're in RFKILL, we
shouldn't wake up the wait queue since we still expect to get all the
notifications from the firmware.

Fixes: 4d08c0b3357c ("wifi: iwlwifi: mvm: handle BA session teardown in RF-kill")
Signed-off-by: Emmanuel Grumbach &lt;emmanuel.grumbach@intel.com&gt;
Signed-off-by: Miri Korenblit &lt;miriam.rachel.korenblit@intel.com&gt;
Link: https://patch.msgid.link/20240703064027.be7a9dbeacde.I5586cb3ca8d6e44f79d819a48a0c22351ff720c9@changeid
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>wifi: mac80211: disable softirqs for queued frame handling</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2024-06-26T07:15:59Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ba780cb0cf9aa80629122dc355fa178dd93ba2d9'/>
<id>urn:sha1:ba780cb0cf9aa80629122dc355fa178dd93ba2d9</id>
<content type='text'>
commit 321028bc45f01edb9e57b0ae5c11c5c3600d00ca upstream.

As noticed by syzbot, calling ieee80211_handle_queued_frames()
(and actually handling frames there) requires softirqs to be
disabled, since we call into the RX code. Fix that in the case
of cleaning up frames left over during shutdown.

Fixes: 177c6ae9725d ("wifi: mac80211: handle tasklet frames before stopping")
Reported-by: syzbot+1d516edf1e74469ba5d3@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20240626091559.cd6f08105a6e.I74778610a5ff2cf8680964698131099d2960352a@changeid
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>wifi: cfg80211: wext: set ssids=NULL for passive scans</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2024-06-11T16:58:16Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=de3994a44ebc6162218dcbc2eeb850dee2b9c277'/>
<id>urn:sha1:de3994a44ebc6162218dcbc2eeb850dee2b9c277</id>
<content type='text'>
commit 0941772342d59e48733131ac3a202fa1a4d832e9 upstream.

In nl80211, we always set the ssids of a scan request to
NULL when n_ssids==0 (passive scan). Drivers have relied
on this behaviour in the past, so we fixed it in 6 GHz
scan requests as well, and added a warning so we'd have
assurance the API would always be called that way.

syzbot found that wext doesn't ensure that, so we reach
the check and trigger the warning. Fix the wext code to
set the ssids pointer to NULL when there are none.

Reported-by: syzbot+cd6135193ba6bb9ad158@syzkaller.appspotmail.com
Fixes: f7a8b10bfd61 ("wifi: cfg80211: fix 6 GHz scan request building")
Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>of/irq: Disable "interrupt-map" parsing for PASEMI Nemo</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2024-07-02T21:42:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9ca15d7699b1649a1b84e05cd9b30cf7ed5e47ca'/>
<id>urn:sha1:9ca15d7699b1649a1b84e05cd9b30cf7ed5e47ca</id>
<content type='text'>
commit 2cf6b7d15a28640117bf9f75dc050892cf78a6e8 upstream.

Once again, we've broken PASEMI Nemo boards with its incomplete
"interrupt-map" translations. Commit 935df1bd40d4 ("of/irq: Factor out
parsing of interrupt-map parent phandle+args from of_irq_parse_raw()")
changed the behavior resulting in the existing work-around not taking
effect. Rework the work-around to just skip parsing "interrupt-map" up
front by using the of_irq_imap_abusers list.

Fixes: 935df1bd40d4 ("of/irq: Factor out parsing of interrupt-map parent phandle+args from of_irq_parse_raw()")
Reported-by: Christian Zigotzky &lt;chzigotzky@xenosoft.de&gt;
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/86ed8ba2sp.wl-maz@kernel.org
Signed-off-by: Rob Herring (Arm) &lt;robh@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Bluetooth: L2CAP: Fix deadlock</title>
<updated>2024-07-25T07:50:57Z</updated>
<author>
<name>Luiz Augusto von Dentz</name>
<email>luiz.von.dentz@intel.com</email>
</author>
<published>2024-06-24T13:42:09Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b0fc1bd2514b96962c6371dff79d2d4df4fafe9e'/>
<id>urn:sha1:b0fc1bd2514b96962c6371dff79d2d4df4fafe9e</id>
<content type='text'>
commit f1a8f402f13f94263cf349216c257b2985100927 upstream.

This fixes the following deadlock introduced by 39a92a55be13
("bluetooth/l2cap: sync sock recv cb and release")

============================================
WARNING: possible recursive locking detected
6.10.0-rc3-g4029dba6b6f1 #6823 Not tainted
--------------------------------------------
kworker/u5:0/35 is trying to acquire lock:
ffff888002ec2510 (&amp;chan-&gt;lock#2/1){+.+.}-{3:3}, at:
l2cap_sock_recv_cb+0x44/0x1e0

but task is already holding lock:
ffff888002ec2510 (&amp;chan-&gt;lock#2/1){+.+.}-{3:3}, at:
l2cap_get_chan_by_scid+0xaf/0xd0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&amp;chan-&gt;lock#2/1);
  lock(&amp;chan-&gt;lock#2/1);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by kworker/u5:0/35:
 #0: ffff888002b8a940 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
process_one_work+0x750/0x930
 #1: ffff888002c67dd0 ((work_completion)(&amp;hdev-&gt;rx_work)){+.+.}-{0:0},
at: process_one_work+0x44e/0x930
 #2: ffff888002ec2510 (&amp;chan-&gt;lock#2/1){+.+.}-{3:3}, at:
l2cap_get_chan_by_scid+0xaf/0xd0

To fix the original problem this introduces l2cap_chan_lock at
l2cap_conless_channel to ensure that l2cap_sock_recv_cb is called with
chan-&gt;lock held.

Fixes: 89e856e124f9 ("bluetooth/l2cap: sync sock recv cb and release")
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>mm: page_ref: remove folio_try_get_rcu()</title>
<updated>2024-07-25T07:50:56Z</updated>
<author>
<name>Yang Shi</name>
<email>yang@os.amperecomputing.com</email>
</author>
<published>2024-06-25T20:53:50Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=16380f52b72166d6a33b508cc2509716f436253f'/>
<id>urn:sha1:16380f52b72166d6a33b508cc2509716f436253f</id>
<content type='text'>
commit fa2690af573dfefb47ba6eef888797a64b6b5f3c upstream.

The below bug was reported on a non-SMP kernel:

[  275.267158][ T4335] ------------[ cut here ]------------
[  275.267949][ T4335] kernel BUG at include/linux/page_ref.h:275!
[  275.268526][ T4335] invalid opcode: 0000 [#1] KASAN PTI
[  275.269001][ T4335] CPU: 0 PID: 4335 Comm: trinity-c3 Not tainted 6.7.0-rc4-00061-gefa7df3e3bb5 #1
[  275.269787][ T4335] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[  275.270679][ T4335] RIP: 0010:try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[  275.272813][ T4335] RSP: 0018:ffffc90005dcf650 EFLAGS: 00010202
[  275.273346][ T4335] RAX: 0000000000000246 RBX: ffffea00066e0000 RCX: 0000000000000000
[  275.274032][ T4335] RDX: fffff94000cdc007 RSI: 0000000000000004 RDI: ffffea00066e0034
[  275.274719][ T4335] RBP: ffffea00066e0000 R08: 0000000000000000 R09: fffff94000cdc006
[  275.275404][ T4335] R10: ffffea00066e0037 R11: 0000000000000000 R12: 0000000000000136
[  275.276106][ T4335] R13: ffffea00066e0034 R14: dffffc0000000000 R15: ffffea00066e0008
[  275.276790][ T4335] FS:  00007fa2f9b61740(0000) GS:ffffffff89d0d000(0000) knlGS:0000000000000000
[  275.277570][ T4335] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  275.278143][ T4335] CR2: 00007fa2f6c00000 CR3: 0000000134b04000 CR4: 00000000000406f0
[  275.278833][ T4335] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  275.279521][ T4335] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  275.280201][ T4335] Call Trace:
[  275.280499][ T4335]  &lt;TASK&gt;
[ 275.280751][ T4335] ? die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434 arch/x86/kernel/dumpstack.c:447)
[ 275.281087][ T4335] ? do_trap (arch/x86/kernel/traps.c:112 arch/x86/kernel/traps.c:153)
[ 275.281463][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.281884][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.282300][ T4335] ? do_error_trap (arch/x86/kernel/traps.c:174)
[ 275.282711][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.283129][ T4335] ? handle_invalid_op (arch/x86/kernel/traps.c:212)
[ 275.283561][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.283990][ T4335] ? exc_invalid_op (arch/x86/kernel/traps.c:264)
[ 275.284415][ T4335] ? asm_exc_invalid_op (arch/x86/include/asm/idtentry.h:568)
[ 275.284859][ T4335] ? try_get_folio (include/linux/page_ref.h:275 (discriminator 3) mm/gup.c:79 (discriminator 3))
[ 275.285278][ T4335] try_grab_folio (mm/gup.c:148)
[ 275.285684][ T4335] __get_user_pages (mm/gup.c:1297 (discriminator 1))
[ 275.286111][ T4335] ? __pfx___get_user_pages (mm/gup.c:1188)
[ 275.286579][ T4335] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825)
[ 275.287034][ T4335] ? mark_lock (kernel/locking/lockdep.c:4656 (discriminator 1))
[ 275.287416][ T4335] __gup_longterm_locked (mm/gup.c:1509 mm/gup.c:2209)
[ 275.288192][ T4335] ? __pfx___gup_longterm_locked (mm/gup.c:2204)
[ 275.288697][ T4335] ? __pfx_lock_acquire (kernel/locking/lockdep.c:5722)
[ 275.289135][ T4335] ? __pfx___might_resched (kernel/sched/core.c:10106)
[ 275.289595][ T4335] pin_user_pages_remote (mm/gup.c:3350)
[ 275.290041][ T4335] ? __pfx_pin_user_pages_remote (mm/gup.c:3350)
[ 275.290545][ T4335] ? find_held_lock (kernel/locking/lockdep.c:5244 (discriminator 1))
[ 275.290961][ T4335] ? mm_access (kernel/fork.c:1573)
[ 275.291353][ T4335] process_vm_rw_single_vec+0x142/0x360
[ 275.291900][ T4335] ? __pfx_process_vm_rw_single_vec+0x10/0x10
[ 275.292471][ T4335] ? mm_access (kernel/fork.c:1573)
[ 275.292859][ T4335] process_vm_rw_core+0x272/0x4e0
[ 275.293384][ T4335] ? hlock_class (arch/x86/include/asm/bitops.h:227 arch/x86/include/asm/bitops.h:239 include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[ 275.293780][ T4335] ? __pfx_process_vm_rw_core+0x10/0x10
[ 275.294350][ T4335] process_vm_rw (mm/process_vm_access.c:284)
[ 275.294748][ T4335] ? __pfx_process_vm_rw (mm/process_vm_access.c:259)
[ 275.295197][ T4335] ? __task_pid_nr_ns (include/linux/rcupdate.h:306 (discriminator 1) include/linux/rcupdate.h:780 (discriminator 1) kernel/pid.c:504 (discriminator 1))
[ 275.295634][ T4335] __x64_sys_process_vm_readv (mm/process_vm_access.c:291)
[ 275.296139][ T4335] ? syscall_enter_from_user_mode (kernel/entry/common.c:94 kernel/entry/common.c:112)
[ 275.296642][ T4335] do_syscall_64 (arch/x86/entry/common.c:51 (discriminator 1) arch/x86/entry/common.c:82 (discriminator 1))
[ 275.297032][ T4335] ? __task_pid_nr_ns (include/linux/rcupdate.h:306 (discriminator 1) include/linux/rcupdate.h:780 (discriminator 1) kernel/pid.c:504 (discriminator 1))
[ 275.297470][ T4335] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359)
[ 275.297988][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.298389][ T4335] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4300 kernel/locking/lockdep.c:4359)
[ 275.298906][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.299304][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.299703][ T4335] ? do_syscall_64 (arch/x86/include/asm/cpufeature.h:171 arch/x86/entry/common.c:97)
[ 275.300115][ T4335] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)

This BUG is the VM_BUG_ON(!in_atomic() &amp;&amp; !irqs_disabled()) assertion in
folio_ref_try_add_rcu() for non-SMP kernel.

The process_vm_readv() calls GUP to pin the THP. An optimization for
pinning THP instroduced by commit 57edfcfd3419 ("mm/gup: accelerate thp
gup even for "pages != NULL"") calls try_grab_folio() to pin the THP,
but try_grab_folio() is supposed to be called in atomic context for
non-SMP kernel, for example, irq disabled or preemption disabled, due to
the optimization introduced by commit e286781d5f2e ("mm: speculative
page references").

The commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP
boundaries") is not actually the root cause although it was bisected to.
It just makes the problem exposed more likely.

The follow up discussion suggested the optimization for non-SMP kernel
may be out-dated and not worth it anymore [1].  So removing the
optimization to silence the BUG.

However calling try_grab_folio() in GUP slow path actually is
unnecessary, so the following patch will clean this up.

[1] https://lore.kernel.org/linux-mm/821cf1d6-92b9-4ac4-bacc-d8f2364ac14f@paulmck-laptop/

Link: https://lkml.kernel.org/r/20240625205350.1777481-1-yang@os.amperecomputing.com
Fixes: 57edfcfd3419 ("mm/gup: accelerate thp gup even for "pages != NULL"")
Signed-off-by: Yang Shi &lt;yang@os.amperecomputing.com&gt;
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Tested-by: Oliver Sang &lt;oliver.sang@intel.com&gt;
Acked-by: Peter Xu &lt;peterx@redhat.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Vivek Kasireddy &lt;vivek.kasireddy@intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[6.6+]
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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