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| author | Mikulas Patocka <mpatocka@redhat.com> | 2024-01-09 15:59:15 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2024-01-30 14:06:44 -0500 |
| commit | 9cf11ce06ea52911245578032761e40a6409cf35 (patch) | |
| tree | c0eee6f11a1148c4d7a509d88d989ecf55df0c26 /drivers/md/dm-stats.c | |
| parent | bd504bcfec41a503b32054da5472904b404341a4 (diff) | |
| download | lwn-9cf11ce06ea52911245578032761e40a6409cf35.tar.gz lwn-9cf11ce06ea52911245578032761e40a6409cf35.zip | |
dm stats: limit the number of entries
The kvmalloc function fails with a warning if the size is larger than
INT_MAX. Linus said that there should be limits that prevent this warning
from being hit. This commit adds the limits to the dm-stats subsystem
in DM core.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md/dm-stats.c')
| -rw-r--r-- | drivers/md/dm-stats.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index bdc14ec99814..1e5d988f44da 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -66,6 +66,9 @@ struct dm_stats_last_position { unsigned int last_rw; }; +#define DM_STAT_MAX_ENTRIES 8388608 +#define DM_STAT_MAX_HISTOGRAM_ENTRIES 134217728 + /* * A typo on the command line could possibly make the kernel run out of memory * and crash. To prevent the crash we account all used memory. We fail if we @@ -285,6 +288,9 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1)) return -EOVERFLOW; + if (n_entries > DM_STAT_MAX_ENTRIES) + return -EOVERFLOW; + shared_alloc_size = struct_size(s, stat_shared, n_entries); if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries) return -EOVERFLOW; @@ -297,6 +303,9 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long)) return -EOVERFLOW; + if ((n_histogram_entries + 1) * (size_t)n_entries > DM_STAT_MAX_HISTOGRAM_ENTRIES) + return -EOVERFLOW; + if (!check_shared_memory(shared_alloc_size + histogram_alloc_size + num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size))) return -ENOMEM; |