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| author | SeongJae Park <sj@kernel.org> | 2022-11-14 17:55:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-02 17:43:10 +0100 |
| commit | dfb8a23d93a6f6c7b3c51f4fb5acdb25e176cd45 (patch) | |
| tree | 32f68a1c120e478831dbe888b3f26e4168784bf4 /mm | |
| parent | 3398bf9b0d12912bfe912b86dcea86527fd85ed8 (diff) | |
| download | linux-dfb8a23d93a6f6c7b3c51f4fb5acdb25e176cd45.tar.gz linux-dfb8a23d93a6f6c7b3c51f4fb5acdb25e176cd45.tar.bz2 linux-dfb8a23d93a6f6c7b3c51f4fb5acdb25e176cd45.zip | |
mm/damon/sysfs-schemes: skip stats update if the scheme directory is removed
commit 8468b486612c808c9e337708d66a435498f1735c upstream.
A DAMON sysfs interface user can start DAMON with a scheme, remove the
sysfs directory for the scheme, and then ask update of the scheme's stats.
Because the schemes stats update logic isn't aware of the situation, it
results in an invalid memory access. Fix the bug by checking if the
scheme sysfs directory exists.
Link: https://lkml.kernel.org/r/20221114175552.1951-1-sj@kernel.org
Fixes: 0ac32b8affb5 ("mm/damon/sysfs: support DAMOS stats")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [v5.18]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/damon/sysfs.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c index bdef9682d0a0..b4b9614eecbe 100644 --- a/mm/damon/sysfs.c +++ b/mm/damon/sysfs.c @@ -2342,6 +2342,10 @@ static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond) damon_for_each_scheme(scheme, ctx) { struct damon_sysfs_stats *sysfs_stats; + /* user could have removed the scheme sysfs dir */ + if (schemes_idx >= sysfs_schemes->nr) + break; + sysfs_stats = sysfs_schemes->schemes_arr[schemes_idx++]->stats; sysfs_stats->nr_tried = scheme->stat.nr_tried; sysfs_stats->sz_tried = scheme->stat.sz_tried; |