linux-stable.git/drivers/block/drbd, branch linux-5.4.y Linux kernel stable tree drbd: add missing kref_get in handle_write_conflicts 2025-08-28T14:21:24+00:00 Sarah Newman srn@prgmr.com 2025-06-27T09:57:28+00:00 0336bfe9c237476bd7c45605a36ca79c2bca62e5 [ Upstream commit 00c9c9628b49e368d140cfa61d7df9b8922ec2a8 ] With `two-primaries` enabled, DRBD tries to detect "concurrent" writes and handle write conflicts, so that even if you write to the same sector simultaneously on both nodes, they end up with the identical data once the writes are completed. In handling "superseeded" writes, we forgot a kref_get, resulting in a premature drbd_destroy_device and use after free, and further to kernel crashes with symptoms. Relevance: No one should use DRBD as a random data generator, and apparently all users of "two-primaries" handle concurrent writes correctly on layer up. That is cluster file systems use some distributed lock manager, and live migration in virtualization environments stops writes on one node before starting writes on the other node. Which means that other than for "test cases", this code path is never taken in real life. FYI, in DRBD 9, things are handled differently nowadays. We still detect "write conflicts", but no longer try to be smart about them. We decided to disconnect hard instead: upper layers must not submit concurrent writes. If they do, that's their fault. Signed-off-by: Sarah Newman <srn@prgmr.com> Signed-off-by: Lars Ellenberg <lars@linbit.com> Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Link: https://lore.kernel.org/r/20250627095728.800688-1-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 00c9c9628b49e368d140cfa61d7df9b8922ec2a8 ]

With `two-primaries` enabled, DRBD tries to detect "concurrent" writes
and handle write conflicts, so that even if you write to the same sector
simultaneously on both nodes, they end up with the identical data once
the writes are completed.

In handling "superseeded" writes, we forgot a kref_get,
resulting in a premature drbd_destroy_device and use after free,
and further to kernel crashes with symptoms.

Relevance: No one should use DRBD as a random data generator, and apparently
all users of "two-primaries" handle concurrent writes correctly on layer up.
That is cluster file systems use some distributed lock manager,
and live migration in virtualization environments stops writes on one node
before starting writes on the other node.

Which means that other than for "test cases",
this code path is never taken in real life.

FYI, in DRBD 9, things are handled differently nowadays.  We still detect
"write conflicts", but no longer try to be smart about them.
We decided to disconnect hard instead: upper layers must not submit concurrent
writes. If they do, that's their fault.

Signed-off-by: Sarah Newman <srn@prgmr.com>
Signed-off-by: Lars Ellenberg <lars@linbit.com>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20250627095728.800688-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drbd: Add NULL check for net_conf to prevent dereference in state validation 2024-11-08T15:20:33+00:00 Mikhail Lobanov m.lobanov@rosalinux.ru 2024-09-09T13:37:36+00:00 959974bf5dd8bd79d106f5e43e48051db3c4c213 commit a5e61b50c9f44c5edb6e134ede6fee8806ffafa9 upstream. If the net_conf pointer is NULL and the code attempts to access its fields without a check, it will lead to a null pointer dereference. Add a NULL check before dereferencing the pointer. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 44ed167da748 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf") Cc: stable@vger.kernel.org Signed-off-by: Mikhail Lobanov <m.lobanov@rosalinux.ru> Link: https://lore.kernel.org/r/20240909133740.84297-1-m.lobanov@rosalinux.ru Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a5e61b50c9f44c5edb6e134ede6fee8806ffafa9 upstream.

If the net_conf pointer is NULL and the code attempts to access its
fields without a check, it will lead to a null pointer dereference.
Add a NULL check before dereferencing the pointer.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 44ed167da748 ("drbd: rcu_read_lock() and rcu_dereference() for tconn->net_conf")
Cc: stable@vger.kernel.org
Signed-off-by: Mikhail Lobanov <m.lobanov@rosalinux.ru>
Link: https://lore.kernel.org/r/20240909133740.84297-1-m.lobanov@rosalinux.ru
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drbd: Fix atomicity violation in drbd_uuid_set_bm() 2024-11-08T15:20:33+00:00 Qiu-ji Chen chenqiuji666@gmail.com 2024-09-13T08:35:04+00:00 9679a6e148d70dbe82d46085b91696fd2bc28e9d commit 2f02b5af3a4482b216e6a466edecf6ba8450fa45 upstream. The violation of atomicity occurs when the drbd_uuid_set_bm function is executed simultaneously with modifying the value of device->ldev->md.uuid[UI_BITMAP]. Consider a scenario where, while device->ldev->md.uuid[UI_BITMAP] passes the validity check when its value is not zero, the value of device->ldev->md.uuid[UI_BITMAP] is written to zero. In this case, the check in drbd_uuid_set_bm might refer to the old value of device->ldev->md.uuid[UI_BITMAP] (before locking), which allows an invalid value to pass the validity check, resulting in inconsistency. To address this issue, it is recommended to include the data validity check within the locked section of the function. This modification ensures that the value of device->ldev->md.uuid[UI_BITMAP] does not change during the validation process, thereby maintaining its integrity. This possible bug is found by an experimental static analysis tool developed by our team. This tool analyzes the locking APIs to extract function pairs that can be concurrently executed, and then analyzes the instructions in the paired functions to identify possible concurrency bugs including data races and atomicity violations. Fixes: 9f2247bb9b75 ("drbd: Protect accesses to the uuid set with a spinlock") Cc: stable@vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666@gmail.com> Reviewed-by: Philipp Reisner <philipp.reisner@linbit.com> Link: https://lore.kernel.org/r/20240913083504.10549-1-chenqiuji666@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2f02b5af3a4482b216e6a466edecf6ba8450fa45 upstream.

The violation of atomicity occurs when the drbd_uuid_set_bm function is
executed simultaneously with modifying the value of
device->ldev->md.uuid[UI_BITMAP]. Consider a scenario where, while
device->ldev->md.uuid[UI_BITMAP] passes the validity check when its
value is not zero, the value of device->ldev->md.uuid[UI_BITMAP] is
written to zero. In this case, the check in drbd_uuid_set_bm might refer
to the old value of device->ldev->md.uuid[UI_BITMAP] (before locking),
which allows an invalid value to pass the validity check, resulting in
inconsistency.

To address this issue, it is recommended to include the data validity
check within the locked section of the function. This modification
ensures that the value of device->ldev->md.uuid[UI_BITMAP] does not
change during the validation process, thereby maintaining its integrity.

This possible bug is found by an experimental static analysis tool
developed by our team. This tool analyzes the locking APIs to extract
function pairs that can be concurrently executed, and then analyzes the
instructions in the paired functions to identify possible concurrency
bugs including data races and atomicity violations.

Fixes: 9f2247bb9b75 ("drbd: Protect accesses to the uuid set with a spinlock")
Cc: stable@vger.kernel.org
Signed-off-by: Qiu-ji Chen <chenqiuji666@gmail.com>
Reviewed-by: Philipp Reisner <philipp.reisner@linbit.com>
Link: https://lore.kernel.org/r/20240913083504.10549-1-chenqiuji666@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
treewide: Remove uninitialized_var() usage 2023-06-09T08:29:01+00:00 Kees Cook keescook@chromium.org 2020-06-03T20:09:38+00:00 0638dcc7e75fbb766761e7b4694d0f0f141bbbd1 commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream. Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drbd: correctly submit flush bio on barrier 2023-05-17T09:36:04+00:00 Christoph Böhmwalder christoph.boehmwalder@linbit.com 2023-05-03T12:19:37+00:00 dde34ef0bc7378ba58fb9e135d2583d2b280dc06 commit 3899d94e3831ee07ea6821c032dc297aec80586a upstream. When we receive a flush command (or "barrier" in DRBD), we currently use a REQ_OP_FLUSH with the REQ_PREFLUSH flag set. The correct way to submit a flush bio is by using a REQ_OP_WRITE without any data, and set the REQ_PREFLUSH flag. Since commit b4a6bb3a67aa ("block: add a sanity check for non-write flush/fua bios"), this triggers a warning in the block layer, but this has been broken for quite some time before that. So use the correct set of flags to actually make the flush happen. Cc: Christoph Hellwig <hch@infradead.org> Cc: stable@vger.kernel.org Fixes: f9ff0da56437 ("drbd: allow parallel flushes for multi-volume resources") Reported-by: Thomas Voegtle <tv@lio96.de> Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230503121937.17232-1-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3899d94e3831ee07ea6821c032dc297aec80586a upstream.

When we receive a flush command (or "barrier" in DRBD), we currently use
a REQ_OP_FLUSH with the REQ_PREFLUSH flag set.

The correct way to submit a flush bio is by using a REQ_OP_WRITE without
any data, and set the REQ_PREFLUSH flag.

Since commit b4a6bb3a67aa ("block: add a sanity check for non-write
flush/fua bios"), this triggers a warning in the block layer, but this
has been broken for quite some time before that.

So use the correct set of flags to actually make the flush happen.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: stable@vger.kernel.org
Fixes: f9ff0da56437 ("drbd: allow parallel flushes for multi-volume resources")
Reported-by: Thomas Voegtle <tv@lio96.de>
Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230503121937.17232-1-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drbd: use after free in drbd_create_device() 2022-11-25T16:42:16+00:00 Dan Carpenter error27@gmail.com 2022-11-15T13:16:43+00:00 813a8dd9c45fd46f5cbbfbedf0791afa7740ccf5 [ Upstream commit a7a1598189228b5007369a9622ccdf587be0730f ] The drbd_destroy_connection() frees the "connection" so use the _safe() iterator to prevent a use after free. Fixes: b6f85ef9538b ("drbd: Iterate over all connections") Signed-off-by: Dan Carpenter <error27@gmail.com> Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Link: https://lore.kernel.org/r/Y3Jd5iZRbNQ9w6gm@kili Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a7a1598189228b5007369a9622ccdf587be0730f ]

The drbd_destroy_connection() frees the "connection" so use the _safe()
iterator to prevent a use after free.

Fixes: b6f85ef9538b ("drbd: Iterate over all connections")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/Y3Jd5iZRbNQ9w6gm@kili
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drbd: fix duplicate array initializer 2022-06-14T16:11:33+00:00 Arnd Bergmann arnd@arndb.de 2022-04-06T19:07:09+00:00 3caa2d7943cab38c3bd6439b37a1825befe462e7 [ Upstream commit 33cb0917bbe241dd17a2b87ead63514c1b7e5615 ] There are two initializers for P_RETRY_WRITE: drivers/block/drbd/drbd_main.c:3676:22: warning: initialized field overwritten [-Woverride-init] Remove the first one since it was already ignored by the compiler and reorder the list to match the enum definition. As P_ZEROES had no entry, add that one instead. Fixes: 036b17eaab93 ("drbd: Receiving part for the PROTOCOL_UPDATE packet") Fixes: f31e583aa2c2 ("drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Link: https://lore.kernel.org/r/20220406190715.1938174-2-christoph.boehmwalder@linbit.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 33cb0917bbe241dd17a2b87ead63514c1b7e5615 ]

There are two initializers for P_RETRY_WRITE:

drivers/block/drbd/drbd_main.c:3676:22: warning: initialized field overwritten [-Woverride-init]

Remove the first one since it was already ignored by the compiler
and reorder the list to match the enum definition. As P_ZEROES had
no entry, add that one instead.

Fixes: 036b17eaab93 ("drbd: Receiving part for the PROTOCOL_UPDATE packet")
Fixes: f31e583aa2c2 ("drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Link: https://lore.kernel.org/r/20220406190715.1938174-2-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drbd: remove usage of list iterator variable after loop 2022-05-25T07:14:32+00:00 Jakob Koschel jakobkoschel@gmail.com 2022-03-31T22:03:48+00:00 232128f6e60f37a98cd6566d6d9685f0d43d0b77 [ Upstream commit 901aeda62efa21f2eae937bccb71b49ae531be06 ] In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to iterate through the list [1]. Since that variable should not be used past the loop iteration, a separate variable is used to 'remember the current location within the loop'. To either continue iterating from that position or skip the iteration (if the previous iteration was complete) list_prepare_entry() is used. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220331220349.885126-1-jakobkoschel@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 901aeda62efa21f2eae937bccb71b49ae531be06 ]

In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to iterate through the list [1].

Since that variable should not be used past the loop iteration, a
separate variable is used to 'remember the current location within the
loop'.

To either continue iterating from that position or skip the iteration
(if the previous iteration was complete) list_prepare_entry() is used.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220331220349.885126-1-jakobkoschel@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
block: drbd: drbd_nl: Make conversion to 'enum drbd_ret_code' explicit 2022-05-15T17:54:46+00:00 Lee Jones lee.jones@linaro.org 2021-03-12T10:55:26+00:00 e6ff94d31c53c5e5ae7d909d44cbc55ecfe725ad commit 1f1e87b4dc4598eac57a69868534b92d65e47e82 upstream. Fixes the following W=1 kernel build warning(s): from drivers/block/drbd/drbd_nl.c:24: drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_set_role’: drivers/block/drbd/drbd_nl.c:793:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion] drivers/block/drbd/drbd_nl.c:795:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion] drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_attach’: drivers/block/drbd/drbd_nl.c:1965:10: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion] drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_connect’: drivers/block/drbd/drbd_nl.c:2690:10: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion] drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_disconnect’: drivers/block/drbd/drbd_nl.c:2803:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion] Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Lars Ellenberg <lars.ellenberg@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: drbd-dev@lists.linbit.com Cc: linux-block@vger.kernel.org Signed-off-by: Lee Jones <lee.jones@linaro.org> Link: https://lore.kernel.org/r/20210312105530.2219008-8-lee.jones@linaro.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1f1e87b4dc4598eac57a69868534b92d65e47e82 upstream.

Fixes the following W=1 kernel build warning(s):

 from drivers/block/drbd/drbd_nl.c:24:
 drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_set_role’:
 drivers/block/drbd/drbd_nl.c:793:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion]
 drivers/block/drbd/drbd_nl.c:795:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion]
 drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_attach’:
 drivers/block/drbd/drbd_nl.c:1965:10: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion]
 drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_connect’:
 drivers/block/drbd/drbd_nl.c:2690:10: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion]
 drivers/block/drbd/drbd_nl.c: In function ‘drbd_adm_disconnect’:
 drivers/block/drbd/drbd_nl.c:2803:11: warning: implicit conversion from ‘enum drbd_state_rv’ to ‘enum drbd_ret_code’ [-Wenum-conversion]

Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210312105530.2219008-8-lee.jones@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drbd: Fix five use after free bugs in get_initial_state 2022-04-15T12:18:38+00:00 Lv Yunlong lyl2019@mail.ustc.edu.cn 2022-04-06T19:04:43+00:00 b6a4055036eed1f5e239ce3d8b0db1ce38bba447 [ Upstream commit aadb22ba2f656581b2f733deb3a467c48cc618f6 ] In get_initial_state, it calls notify_initial_state_done(skb,..) if cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(), the skb will be freed by nlmsg_free(skb). Then get_initial_state will goto out and the freed skb will be used by return value skb->len, which is a uaf bug. What's worse, the same problem goes even further: skb can also be freed in the notify_*_state_change -> notify_*_state calls below. Thus 4 additional uaf bugs happened. My patch lets the problem callee functions: notify_initial_state_done and notify_*_state_change return an error code if errors happen. So that the error codes could be propagated and the uaf bugs can be avoid. v2 reports a compilation warning. This v3 fixed this warning and built successfully in my local environment with no additional warnings. v2: https://lore.kernel.org/patchwork/patch/1435218/ Fixes: a29728463b254 ("drbd: Backport the "events2" command") Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aadb22ba2f656581b2f733deb3a467c48cc618f6 ]

In get_initial_state, it calls notify_initial_state_done(skb,..) if
cb->args[5]==1. If genlmsg_put() failed in notify_initial_state_done(),
the skb will be freed by nlmsg_free(skb).
Then get_initial_state will goto out and the freed skb will be used by
return value skb->len, which is a uaf bug.

What's worse, the same problem goes even further: skb can also be
freed in the notify_*_state_change -> notify_*_state calls below.
Thus 4 additional uaf bugs happened.

My patch lets the problem callee functions: notify_initial_state_done
and notify_*_state_change return an error code if errors happen.
So that the error codes could be propagated and the uaf bugs can be avoid.

v2 reports a compilation warning. This v3 fixed this warning and built
successfully in my local environment with no additional warnings.
v2: https://lore.kernel.org/patchwork/patch/1435218/

Fixes: a29728463b254 ("drbd: Backport the "events2" command")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>