linux-stable.git, branch v6.2.11 Linux kernel stable tree Linux 6.2.11 2023-04-13T15:02:59+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2023-04-13T15:02:59+00:00 cdc7aff9ed012801e62eedd99e4a5573eccac4db Link: https://lore.kernel.org/r/20230412082838.125271466@linuxfoundation.org Tested-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Markus Reichelt <lkt+2023@mareichelt.com> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Shuah Khan <skhan@linuxfoundation.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Slade Watkins <srw@sladewatkins.net> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Link: https://lore.kernel.org/r/20230412082838.125271466@linuxfoundation.org
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Ronald Warsow <rwarsow@gmx.de>
Tested-by: Markus Reichelt <lkt+2023@mareichelt.com>
Tested-by: Justin M. Forbes <jforbes@fedoraproject.org>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Ron Economos <re@w6rz.net>
Tested-by: Slade Watkins <srw@sladewatkins.net>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm: enable maple tree RCU mode by default. 2023-04-13T15:02:59+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:55+00:00 ca9bbfd4be0d4cc628f56cb2489204b45b3d3a5a commit 3dd4432549415f3c65dd52d5c687629efbf4ece1 upstream. Use the maple tree in RCU mode for VMA tracking. The maple tree tracks the stack and is able to update the pivot (lower/upper boundary) in-place to allow the page fault handler to write to the tree while holding just the mmap read lock. This is safe as the writes to the stack have a guard VMA which ensures there will always be a NULL in the direction of the growth and thus will only update a pivot. It is possible, but not recommended, to have VMAs that grow up/down without guard VMAs. syzbot has constructed a testcase which sets up a VMA to grow and consume the empty space. Overwriting the entire NULL entry causes the tree to be altered in a way that is not safe for concurrent readers; the readers may see a node being rewritten or one that does not match the maple state they are using. Enabling RCU mode allows the concurrent readers to see a stable node and will return the expected result. Link: https://lkml.kernel.org/r/20230227173632.3292573-9-surenb@google.com Cc: stable@vger.kernel.org Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: syzbot+8d95422d3537159ca390@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3dd4432549415f3c65dd52d5c687629efbf4ece1 upstream.

Use the maple tree in RCU mode for VMA tracking.

The maple tree tracks the stack and is able to update the pivot
(lower/upper boundary) in-place to allow the page fault handler to write
to the tree while holding just the mmap read lock.  This is safe as the
writes to the stack have a guard VMA which ensures there will always be
a NULL in the direction of the growth and thus will only update a pivot.

It is possible, but not recommended, to have VMAs that grow up/down
without guard VMAs.  syzbot has constructed a testcase which sets up a
VMA to grow and consume the empty space.  Overwriting the entire NULL
entry causes the tree to be altered in a way that is not safe for
concurrent readers; the readers may see a node being rewritten or one
that does not match the maple state they are using.

Enabling RCU mode allows the concurrent readers to see a stable node and
will return the expected result.

Link: https://lkml.kernel.org/r/20230227173632.3292573-9-surenb@google.com
Cc: stable@vger.kernel.org
Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: syzbot+8d95422d3537159ca390@syzkaller.appspotmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: add RCU lock checking to rcu callback functions 2023-04-13T15:02:59+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:54+00:00 a4ea73e99e93d9910a5f9818d4aa9fb40f244bdc commit 790e1fa86b340c2bd4a327e01c161f7a1ad885f6 upstream. Dereferencing RCU objects within the RCU callback without the RCU check has caused lockdep to complain. Fix the RCU dereferencing by using the RCU callback lock to ensure the operation is safe. Also stop creating a new lock to use for dereferencing during destruction of the tree or subtree. Instead, pass through a pointer to the tree that has the lock that is held for RCU dereferencing checking. It also does not make sense to use the maple state in the freeing scenario as the tree walk is a special case where the tree no longer has the normal encodings and parent pointers. Link: https://lkml.kernel.org/r/20230227173632.3292573-8-surenb@google.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: stable@vger.kernel.org Reported-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 790e1fa86b340c2bd4a327e01c161f7a1ad885f6 upstream.

Dereferencing RCU objects within the RCU callback without the RCU check
has caused lockdep to complain.  Fix the RCU dereferencing by using the
RCU callback lock to ensure the operation is safe.

Also stop creating a new lock to use for dereferencing during destruction
of the tree or subtree.  Instead, pass through a pointer to the tree that
has the lock that is held for RCU dereferencing checking.  It also does
not make sense to use the maple state in the freeing scenario as the tree
walk is a special case where the tree no longer has the normal encodings
and parent pointers.

Link: https://lkml.kernel.org/r/20230227173632.3292573-8-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: stable@vger.kernel.org
Reported-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: add smp_rmb() to dead node detection 2023-04-13T15:02:59+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:53+00:00 0644026e7717fc8ebe37ff49111b1a5081c5bfae commit 0a2b18d948838e16912b3b627b504ab062b7d02a upstream. Add an smp_rmb() before reading the parent pointer to ensure that anything read from the node prior to the parent pointer hasn't been reordered ahead of this check. The is necessary for RCU mode. Link: https://lkml.kernel.org/r/20230227173632.3292573-7-surenb@google.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: stable@vger.kernel.org Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0a2b18d948838e16912b3b627b504ab062b7d02a upstream.

Add an smp_rmb() before reading the parent pointer to ensure that anything
read from the node prior to the parent pointer hasn't been reordered ahead
of this check.

The is necessary for RCU mode.

Link: https://lkml.kernel.org/r/20230227173632.3292573-7-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: stable@vger.kernel.org
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: remove extra smp_wmb() from mas_dead_leaves() 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:52+00:00 425e737db89bd9774ae4fdd51f93fc5f8bb63c9e commit 8372f4d83f96f35915106093cde4565836587123 upstream. The call to mte_set_dead_node() before the smp_wmb() already calls smp_wmb() so this is not needed. This is an optimization for the RCU mode of the maple tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-5-surenb@google.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: stable@vger.kernel.org Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8372f4d83f96f35915106093cde4565836587123 upstream.

The call to mte_set_dead_node() before the smp_wmb() already calls
smp_wmb() so this is not needed.  This is an optimization for the RCU mode
of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-5-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: stable@vger.kernel.org
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: fix freeing of nodes in rcu mode 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:51+00:00 bc5ab3677b2bd17b127dd9a5a9c2c81799b092ef commit 2e5b4921f8efc9e845f4f04741797d16f36847eb upstream. The walk to destroy the nodes was not always setting the node type and would result in a destroy method potentially using the values as nodes. Avoid this by setting the correct node types. This is necessary for the RCU mode of the maple tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-4-surenb@google.com Cc: <Stable@vger.kernel.org> Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2e5b4921f8efc9e845f4f04741797d16f36847eb upstream.

The walk to destroy the nodes was not always setting the node type and
would result in a destroy method potentially using the values as nodes.
Avoid this by setting the correct node types.  This is necessary for the
RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-4-surenb@google.com
Cc: <Stable@vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: detect dead nodes in mas_start() 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:50+00:00 237a5a21293e52d2085670ed666291c87eafae59 commit a7b92d59c885018cb7bb88539892278e4fd64b29 upstream. When initially starting a search, the root node may already be in the process of being replaced in RCU mode. Detect and restart the walk if this is the case. This is necessary for RCU mode of the maple tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-3-surenb@google.com Cc: <Stable@vger.kernel.org> Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a7b92d59c885018cb7bb88539892278e4fd64b29 upstream.

When initially starting a search, the root node may already be in the
process of being replaced in RCU mode.  Detect and restart the walk if
this is the case.  This is necessary for RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-3-surenb@google.com
Cc: <Stable@vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: refine ma_state init from mas_start() 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:49+00:00 e2ce46b027fd2598f92ddafe7cd43a3ff1aaa9f7 commit 46b345848261009477552d654cb2f65000c30e4d upstream. If mas->node is an MAS_START, there are three cases, and they all assign different values to mas->node and mas->offset. So there is no need to set them to a default value before updating. Update them directly to make them easier to understand and for better readability. Link: https://lkml.kernel.org/r/20221221060058.609003-7-vernon2gm@gmail.com Cc: <Stable@vger.kernel.org> Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Vernon Yang <vernon2gm@gmail.com> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 46b345848261009477552d654cb2f65000c30e4d upstream.

If mas->node is an MAS_START, there are three cases, and they all assign
different values to mas->node and mas->offset.  So there is no need to set
them to a default value before updating.

Update them directly to make them easier to understand and for better
readability.

Link: https://lkml.kernel.org/r/20221221060058.609003-7-vernon2gm@gmail.com
Cc: <Stable@vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Vernon Yang <vernon2gm@gmail.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: be more cautious about dead nodes 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:48+00:00 9efd643fb394061aaf6de7aa82609915dc34266f commit 39d0bd86c499ecd6abae42a9b7112056c5560691 upstream. ma_pivots() and ma_data_end() may be called with a dead node. Ensure to that the node isn't dead before using the returned values. This is necessary for RCU mode of the maple tree. Link: https://lkml.kernel.org/r/20230227173632.3292573-1-surenb@google.com Link: https://lkml.kernel.org/r/20230227173632.3292573-2-surenb@google.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Cc: <Stable@vger.kernel.org> Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 39d0bd86c499ecd6abae42a9b7112056c5560691 upstream.

ma_pivots() and ma_data_end() may be called with a dead node.  Ensure to
that the node isn't dead before using the returned values.

This is necessary for RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-1-surenb@google.com
Link: https://lkml.kernel.org/r/20230227173632.3292573-2-surenb@google.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
maple_tree: fix mas_prev() and mas_find() state handling 2023-04-13T15:02:58+00:00 Liam R. Howlett Liam.Howlett@Oracle.com 2023-04-11T15:10:46+00:00 33b4fbb261ab1d6756f8cf151f68d64319a16ef8 commit 17dc622c7b0f94e49bed030726df4db12ecaa6b5 upstream. When mas_prev() does not find anything, set the state to MAS_NONE. Handle the MAS_NONE in mas_find() like a MAS_START. Link: https://lkml.kernel.org/r/20230120162650.984577-7-Liam.Howlett@oracle.com Cc: <Stable@vger.kernel.org> Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reported-by: <syzbot+502859d610c661e56545@syzkaller.appspotmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 17dc622c7b0f94e49bed030726df4db12ecaa6b5 upstream.

When mas_prev() does not find anything, set the state to MAS_NONE.

Handle the MAS_NONE in mas_find() like a MAS_START.

Link: https://lkml.kernel.org/r/20230120162650.984577-7-Liam.Howlett@oracle.com
Cc: <Stable@vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: <syzbot+502859d610c661e56545@syzkaller.appspotmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>