The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x 857ccfc19f9be1269716f3d681650c1bd149a656
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091303-unstaffed-specimen-7319@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 857ccfc19f9be1269716f3d681650c1bd149a656 Mon Sep 17 00:00:00 2001
From: Pratap Nirujogi <pratap.nirujogi(a)amd.com>
Date: Wed, 3 Sep 2025 16:00:24 -0400
Subject: [PATCH] drm/amd/amdgpu: Declare isp firmware binary file
Declare isp firmware file isp_4_1_1.bin required by isp4.1.1 device.
Suggested-by: Alexey Zagorodnikov <xglooom(a)gmail.com>
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Signed-off-by: Pratap Nirujogi <pratap.nirujogi(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
(cherry picked from commit d97b74a833eba1f4f69f67198fd98ef036c0e5f9)
Cc: stable(a)vger.kernel.org
diff --git a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c b/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
index a887df520414..4258d3e0b706 100644
--- a/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/isp_v4_1_1.c
@@ -29,6 +29,8 @@
#include "amdgpu.h"
#include "isp_v4_1_1.h"
+MODULE_FIRMWARE("amdgpu/isp_4_1_1.bin");
+
#define ISP_PERFORMANCE_STATE_LOW 0
#define ISP_PERFORMANCE_STATE_HIGH 1
The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x 60f71f0db7b12f303789ef59949e38ee5838ee8b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091312-armful-thus-2400@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 60f71f0db7b12f303789ef59949e38ee5838ee8b Mon Sep 17 00:00:00 2001
From: "Mario Limonciello (AMD)" <mario.limonciello(a)amd.com>
Date: Fri, 5 Sep 2025 10:36:27 -0500
Subject: [PATCH] drm/amd/display: Drop dm_prepare_suspend() and dm_complete()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
[Why]
dm_prepare_suspend() was added in commit 50e0bae34fa6b
("drm/amd/display: Add and use new dm_prepare_suspend() callback")
to allow display to turn off earlier in the suspend sequence.
This caused a regression that HDMI audio sometimes didn't work
properly after resume unless audio was playing during suspend.
[How]
Drop dm_prepare_suspend() callback. All code in it will still run
during dm_suspend(). Also drop unnecessary dm_complete() callback.
dm_complete() was used for failed prepare and also for any case
of successful resume. The code in it already runs in dm_resume().
This change will introduce more time that the display is turned on
during suspend sequence. The compositor can turn it off sooner if
desired.
Cc: Harry Wentland <harry.wentland(a)amd.com>
Reported-by: Przemysław Kopa <prz.kopa(a)gmail.com>
Closes: https://lore.kernel.org/amd-gfx/1cea0d56-7739-4ad9-bf8e-c9330faea2bb@kernel…
Reported-by: Kalvin <hikaph+oss(a)gmail.com>
Closes: https://github.com/alsa-project/alsa-lib/issues/465
Closes: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/4809
Fixes: 50e0bae34fa6b ("drm/amd/display: Add and use new dm_prepare_suspend() callback")
Signed-off-by: Mario Limonciello <mario.limonciello(a)amd.com>
Acked-by: Alex Deucher <alexander.deucher(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
(cherry picked from commit 2fd653b9bb5aacec5d4c421ab290905898fe85a2)
Cc: stable(a)vger.kernel.org
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 7808a647a306..352b3dcd0e0e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3127,25 +3127,6 @@ static void dm_destroy_cached_state(struct amdgpu_device *adev)
dm->cached_state = NULL;
}
-static void dm_complete(struct amdgpu_ip_block *ip_block)
-{
- struct amdgpu_device *adev = ip_block->adev;
-
- dm_destroy_cached_state(adev);
-}
-
-static int dm_prepare_suspend(struct amdgpu_ip_block *ip_block)
-{
- struct amdgpu_device *adev = ip_block->adev;
-
- if (amdgpu_in_reset(adev))
- return 0;
-
- WARN_ON(adev->dm.cached_state);
-
- return dm_cache_state(adev);
-}
-
static int dm_suspend(struct amdgpu_ip_block *ip_block)
{
struct amdgpu_device *adev = ip_block->adev;
@@ -3571,10 +3552,8 @@ static const struct amd_ip_funcs amdgpu_dm_funcs = {
.early_fini = amdgpu_dm_early_fini,
.hw_init = dm_hw_init,
.hw_fini = dm_hw_fini,
- .prepare_suspend = dm_prepare_suspend,
.suspend = dm_suspend,
.resume = dm_resume,
- .complete = dm_complete,
.is_idle = dm_is_idle,
.wait_for_idle = dm_wait_for_idle,
.check_soft_reset = dm_check_soft_reset,
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 711f19dfd783ffb37ca4324388b9c4cb87e71363
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091317-snowsuit-earthen-6ad7@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 711f19dfd783ffb37ca4324388b9c4cb87e71363 Mon Sep 17 00:00:00 2001
From: Quanmin Yan <yanquanmin1(a)huawei.com>
Date: Wed, 27 Aug 2025 19:58:57 +0800
Subject: [PATCH] mm/damon/lru_sort: avoid divide-by-zero in
damon_lru_sort_apply_parameters()
Patch series "mm/damon: avoid divide-by-zero in DAMON module's parameters
application".
DAMON's RECLAIM and LRU_SORT modules perform no validation on
user-configured parameters during application, which may lead to
division-by-zero errors.
Avoid the divide-by-zero by adding validation checks when DAMON modules
attempt to apply the parameters.
This patch (of 2):
During the calculation of 'hot_thres' and 'cold_thres', either
'sample_interval' or 'aggr_interval' is used as the divisor, which may
lead to division-by-zero errors. Fix it by directly returning -EINVAL
when such a case occurs. Additionally, since 'aggr_interval' is already
required to be set no smaller than 'sample_interval' in damon_set_attrs(),
only the case where 'sample_interval' is zero needs to be checked.
Link: https://lkml.kernel.org/r/20250827115858.1186261-2-yanquanmin1@huawei.com
Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: Quanmin Yan <yanquanmin1(a)huawei.com>
Reviewed-by: SeongJae Park <sj(a)kernel.org>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: ze zuo <zuoze1(a)huawei.com>
Cc: <stable(a)vger.kernel.org> [6.0+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 151a9de5ad8b..b5a5ed16a7a5 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -198,6 +198,11 @@ static int damon_lru_sort_apply_parameters(void)
if (err)
return err;
+ if (!damon_lru_sort_mon_attrs.sample_interval) {
+ err = -EINVAL;
+ goto out;
+ }
+
err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
if (err)
goto out;
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x ce652aac9c90a96c6536681d17518efb1f660fb8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091357-stapling-walrus-d0f7@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ce652aac9c90a96c6536681d17518efb1f660fb8 Mon Sep 17 00:00:00 2001
From: Sang-Heon Jeon <ekffu200098(a)gmail.com>
Date: Fri, 22 Aug 2025 11:50:57 +0900
Subject: [PATCH] mm/damon/core: set quota->charged_from to jiffies at first
charge window
Kernel initializes the "jiffies" timer as 5 minutes below zero, as shown
in include/linux/jiffies.h
/*
* Have the 32 bit jiffies value wrap 5 minutes after boot
* so jiffies wrap bugs show up earlier.
*/
#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))
And jiffies comparison help functions cast unsigned value to signed to
cover wraparound
#define time_after_eq(a,b) \
(typecheck(unsigned long, a) && \
typecheck(unsigned long, b) && \
((long)((a) - (b)) >= 0))
When quota->charged_from is initialized to 0, time_after_eq() can
incorrectly return FALSE even after reset_interval has elapsed. This
occurs when (jiffies - reset_interval) produces a value with MSB=1, which
is interpreted as negative in signed arithmetic.
This issue primarily affects 32-bit systems because: On 64-bit systems:
MSB=1 values occur after ~292 million years from boot (assuming HZ=1000),
almost impossible.
On 32-bit systems: MSB=1 values occur during the first 5 minutes after
boot, and the second half of every jiffies wraparound cycle, starting from
day 25 (assuming HZ=1000)
When above unexpected FALSE return from time_after_eq() occurs, the
charging window will not reset. The user impact depends on esz value at
that time.
If esz is 0, scheme ignores configured quotas and runs without any limits.
If esz is not 0, scheme stops working once the quota is exhausted. It
remains until the charging window finally resets.
So, change quota->charged_from to jiffies at damos_adjust_quota() when it
is considered as the first charge window. By this change, we can avoid
unexpected FALSE return from time_after_eq()
Link: https://lkml.kernel.org/r/20250822025057.1740854-1-ekffu200098@gmail.com
Fixes: 2b8a248d5873 ("mm/damon/schemes: implement size quota for schemes application speed control") # 5.16
Signed-off-by: Sang-Heon Jeon <ekffu200098(a)gmail.com>
Reviewed-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 106ee8b0f2d5..c2e0b469fd43 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -2111,6 +2111,10 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s)
if (!quota->ms && !quota->sz && list_empty("a->goals))
return;
+ /* First charge window */
+ if (!quota->total_charged_sz && !quota->charged_from)
+ quota->charged_from = jiffies;
+
/* New charge window starts */
if (time_after_eq(jiffies, quota->charged_from +
msecs_to_jiffies(quota->reset_interval))) {
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 9786531399a679fc2f4630d2c0a186205282ab2f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091346-suspect-numerate-b884@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9786531399a679fc2f4630d2c0a186205282ab2f Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu(a)suse.com>
Date: Fri, 22 Aug 2025 16:06:13 +0930
Subject: [PATCH] btrfs: fix corruption reading compressed range when block
size is smaller than page size
[BUG]
With 64K page size (aarch64 with 64K page size config) and 4K btrfs
block size, the following workload can easily lead to a corrupted read:
mkfs.btrfs -f -s 4k $dev > /dev/null
mount -o compress $dev $mnt
xfs_io -f -c "pwrite -S 0xff 0 64k" $mnt/base > /dev/null
echo "correct result:"
od -Ad -t x1 $mnt/base
xfs_io -f -c "reflink $mnt/base 32k 0 32k" \
-c "reflink $mnt/base 0 32k 32k" \
-c "pwrite -S 0xff 60k 4k" $mnt/new > /dev/null
echo "incorrect result:"
od -Ad -t x1 $mnt/new
umount $mnt
This shows the following result:
correct result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
incorrect result:
0000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0032768 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
*
0061440 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
*
0065536
Notice the zero in the range [32K, 60K), which is incorrect.
[CAUSE]
With extra trace printk, it shows the following events during od:
(some unrelated info removed like CPU and context)
od-3457 btrfs_do_readpage: enter r/i=5/258 folio=0(65536) prev_em_start=0000000000000000
The "r/i" is indicating the root and inode number. In our case the file
"new" is using ino 258 from fs tree (root 5).
Here notice the @prev_em_start pointer is NULL. This means the
btrfs_do_readpage() is called from btrfs_read_folio(), not from
btrfs_readahead().
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=0 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=4096 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=8192 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=12288 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=16384 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=20480 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=24576 got em start=0 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=28672 got em start=0 len=32768
These above 32K blocks will be read from the first half of the
compressed data extent.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=32768 got em start=32768 len=32768
Note here there is no btrfs_submit_compressed_read() call. Which is
incorrect now.
Although both extent maps at 0 and 32K are pointing to the same compressed
data, their offsets are different thus can not be merged into the same
read.
So this means the compressed data read merge check is doing something
wrong.
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=36864 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=40960 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=45056 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=49152 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=53248 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=57344 got em start=32768 len=32768
od-3457 btrfs_do_readpage: r/i=5/258 folio=0(65536) cur=61440 skip uptodate
od-3457 btrfs_submit_compressed_read: cb orig_bio: file off=0 len=61440
The function btrfs_submit_compressed_read() is only called at the end of
folio read. The compressed bio will only have an extent map of range [0,
32K), but the original bio passed in is for the whole 64K folio.
This will cause the decompression part to only fill the first 32K,
leaving the rest untouched (aka, filled with zero).
This incorrect compressed read merge leads to the above data corruption.
There were similar problems that happened in the past, commit 808f80b46790
("Btrfs: update fix for read corruption of compressed and shared
extents") is doing pretty much the same fix for readahead.
But that's back to 2015, where btrfs still only supports bs (block size)
== ps (page size) cases.
This means btrfs_do_readpage() only needs to handle a folio which
contains exactly one block.
Only btrfs_readahead() can lead to a read covering multiple blocks.
Thus only btrfs_readahead() passes a non-NULL @prev_em_start pointer.
With v5.15 kernel btrfs introduced bs < ps support. This breaks the above
assumption that a folio can only contain one block.
Now btrfs_read_folio() can also read multiple blocks in one go.
But btrfs_read_folio() doesn't pass a @prev_em_start pointer, thus the
existing bio force submission check will never be triggered.
In theory, this can also happen for btrfs with large folios, but since
large folio is still experimental, we don't need to bother it, thus only
bs < ps support is affected for now.
[FIX]
Instead of passing @prev_em_start to do the proper compressed extent
check, introduce one new member, btrfs_bio_ctrl::last_em_start, so that
the existing bio force submission logic will always be triggered.
CC: stable(a)vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana(a)suse.com>
Signed-off-by: Qu Wenruo <wqu(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c953297aa89a..b21cb72835cc 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -111,6 +111,24 @@ struct btrfs_bio_ctrl {
*/
unsigned long submit_bitmap;
struct readahead_control *ractl;
+
+ /*
+ * The start offset of the last used extent map by a read operation.
+ *
+ * This is for proper compressed read merge.
+ * U64_MAX means we are starting the read and have made no progress yet.
+ *
+ * The current btrfs_bio_is_contig() only uses disk_bytenr as
+ * the condition to check if the read can be merged with previous
+ * bio, which is not correct. E.g. two file extents pointing to the
+ * same extent but with different offset.
+ *
+ * So here we need to do extra checks to only merge reads that are
+ * covered by the same extent map.
+ * Just extent_map::start will be enough, as they are unique
+ * inside the same inode.
+ */
+ u64 last_em_start;
};
static void submit_one_bio(struct btrfs_bio_ctrl *bio_ctrl)
@@ -909,7 +927,7 @@ static void btrfs_readahead_expand(struct readahead_control *ractl,
* return 0 on success, otherwise return error
*/
static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
- struct btrfs_bio_ctrl *bio_ctrl, u64 *prev_em_start)
+ struct btrfs_bio_ctrl *bio_ctrl)
{
struct inode *inode = folio->mapping->host;
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
@@ -1019,12 +1037,11 @@ static int btrfs_do_readpage(struct folio *folio, struct extent_map **em_cached,
* non-optimal behavior (submitting 2 bios for the same extent).
*/
if (compress_type != BTRFS_COMPRESS_NONE &&
- prev_em_start && *prev_em_start != (u64)-1 &&
- *prev_em_start != em->start)
+ bio_ctrl->last_em_start != U64_MAX &&
+ bio_ctrl->last_em_start != em->start)
force_bio_submit = true;
- if (prev_em_start)
- *prev_em_start = em->start;
+ bio_ctrl->last_em_start = em->start;
btrfs_free_extent_map(em);
em = NULL;
@@ -1238,12 +1255,15 @@ int btrfs_read_folio(struct file *file, struct folio *folio)
const u64 start = folio_pos(folio);
const u64 end = start + folio_size(folio) - 1;
struct extent_state *cached_state = NULL;
- struct btrfs_bio_ctrl bio_ctrl = { .opf = REQ_OP_READ };
+ struct btrfs_bio_ctrl bio_ctrl = {
+ .opf = REQ_OP_READ,
+ .last_em_start = U64_MAX,
+ };
struct extent_map *em_cached = NULL;
int ret;
lock_extents_for_read(inode, start, end, &cached_state);
- ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl, NULL);
+ ret = btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
btrfs_free_extent_map(em_cached);
@@ -2583,7 +2603,8 @@ void btrfs_readahead(struct readahead_control *rac)
{
struct btrfs_bio_ctrl bio_ctrl = {
.opf = REQ_OP_READ | REQ_RAHEAD,
- .ractl = rac
+ .ractl = rac,
+ .last_em_start = U64_MAX,
};
struct folio *folio;
struct btrfs_inode *inode = BTRFS_I(rac->mapping->host);
@@ -2591,12 +2612,11 @@ void btrfs_readahead(struct readahead_control *rac)
const u64 end = start + readahead_length(rac) - 1;
struct extent_state *cached_state = NULL;
struct extent_map *em_cached = NULL;
- u64 prev_em_start = (u64)-1;
lock_extents_for_read(inode, start, end, &cached_state);
while ((folio = readahead_folio(rac)) != NULL)
- btrfs_do_readpage(folio, &em_cached, &bio_ctrl, &prev_em_start);
+ btrfs_do_readpage(folio, &em_cached, &bio_ctrl);
btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state);
The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x 3260a3f0828e06f5f13fac69fb1999a6d60d9cff
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025091318-salsa-tarantula-9209@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3260a3f0828e06f5f13fac69fb1999a6d60d9cff Mon Sep 17 00:00:00 2001
From: Stanislav Fort <stanislav.fort(a)aisle.com>
Date: Fri, 5 Sep 2025 13:10:46 +0300
Subject: [PATCH] mm/damon/sysfs: fix use-after-free in state_show()
state_show() reads kdamond->damon_ctx without holding damon_sysfs_lock.
This allows a use-after-free race:
CPU 0 CPU 1
----- -----
state_show() damon_sysfs_turn_damon_on()
ctx = kdamond->damon_ctx; mutex_lock(&damon_sysfs_lock);
damon_destroy_ctx(kdamond->damon_ctx);
kdamond->damon_ctx = NULL;
mutex_unlock(&damon_sysfs_lock);
damon_is_running(ctx); /* ctx is freed */
mutex_lock(&ctx->kdamond_lock); /* UAF */
(The race can also occur with damon_sysfs_kdamonds_rm_dirs() and
damon_sysfs_kdamond_release(), which free or replace the context under
damon_sysfs_lock.)
Fix by taking damon_sysfs_lock before dereferencing the context, mirroring
the locking used in pid_show().
The bug has existed since state_show() first accessed kdamond->damon_ctx.
Link: https://lkml.kernel.org/r/20250905101046.2288-1-disclosure@aisle.com
Fixes: a61ea561c871 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring")
Signed-off-by: Stanislav Fort <disclosure(a)aisle.com>
Reported-by: Stanislav Fort <disclosure(a)aisle.com>
Reviewed-by: SeongJae Park <sj(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 6d2b0dab50cb..7b9254cadd5f 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1260,14 +1260,18 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
{
struct damon_sysfs_kdamond *kdamond = container_of(kobj,
struct damon_sysfs_kdamond, kobj);
- struct damon_ctx *ctx = kdamond->damon_ctx;
- bool running;
+ struct damon_ctx *ctx;
+ bool running = false;
- if (!ctx)
- running = false;
- else
+ if (!mutex_trylock(&damon_sysfs_lock))
+ return -EBUSY;
+
+ ctx = kdamond->damon_ctx;
+ if (ctx)
running = damon_is_running(ctx);
+ mutex_unlock(&damon_sysfs_lock);
+
return sysfs_emit(buf, "%s\n", running ?
damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_OFF]);