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author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2014-05-17 20:56:38 +0900 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2014-12-14 16:23:47 +0000 |
commit | 73a38fc3d805dadd393453b92d797d5fc08b5641 (patch) | |
tree | 5c1b488b5097f0bd46412d8affc6fd738fd8379e /fs | |
parent | 7927bb3cb4988170bc9c017fa12e188ae13dd5cb (diff) | |
download | kernel_samsung_smdk4412-73a38fc3d805dadd393453b92d797d5fc08b5641.zip kernel_samsung_smdk4412-73a38fc3d805dadd393453b92d797d5fc08b5641.tar.gz kernel_samsung_smdk4412-73a38fc3d805dadd393453b92d797d5fc08b5641.tar.bz2 |
fs: Fix theoretical division by 0 in super_cache_scan().
commit 475d0db742e3755c6b267f48577ff7cbb7dfda0d upstream.
total_objects could be 0 and is used as a denom.
While total_objects is a "long", total_objects == 0 unlikely happens for
3.12 and later kernels because 32-bit architectures would not be able to
hold (1 << 32) objects. However, total_objects == 0 may happen for kernels
between 3.1 and 3.11 because total_objects in prune_super() was an "int"
and (e.g.) x86_64 architecture might be able to hold (1 << 32) objects.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/super.c | 2 |
1 files changed, 2 insertions, 0 deletions
@@ -68,6 +68,8 @@ static int prune_super(struct shrinker *shrink, struct shrink_control *sc) total_objects = sb->s_nr_dentry_unused + sb->s_nr_inodes_unused + fs_objects + 1; + if (!total_objects) + total_objects = 1; if (sc->nr_to_scan) { int dentries; |