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| author | Luis Henriques <luis.henriques@canonical.com> | 2015-09-17 16:01:40 -0700 |
|---|---|---|
| committer | Simon Shields <keepcalm444@gmail.com> | 2016-06-13 14:47:42 +1000 |
| commit | 6726c46cea51720ece973296c30b2b57e209a14b (patch) | |
| tree | 3aa353437cefb5edad7b6be966fac0427c11363f /drivers | |
| parent | 3053323261efed3e9000998136e86f007b52ba73 (diff) | |
| download | kernel_samsung_smdk4412-6726c46cea51720ece973296c30b2b57e209a14b.zip kernel_samsung_smdk4412-6726c46cea51720ece973296c30b2b57e209a14b.tar.gz kernel_samsung_smdk4412-6726c46cea51720ece973296c30b2b57e209a14b.tar.bz2 | |
zram: fix possible use after free in zcomp_create()
zcomp_create() verifies the success of zcomp_strm_{multi,single}_create()
through comp->stream, which can potentially be pointing to memory that
was freed if these functions returned an error.
While at it, replace a 'ERR_PTR(-ENOMEM)' by a more generic
'ERR_PTR(error)' as in the future zcomp_strm_{multi,siggle}_create()
could return other error codes. Function documentation updated
accordingly.
Change-Id: I84334ce1929c8212aa70387781ef0a6b0af50fa5
Fixes: beca3ec71fe5 ("zram: add multi stream functionality")
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/zram/zcomp.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c index f1ff39a..54d946a 100644 --- a/drivers/block/zram/zcomp.c +++ b/drivers/block/zram/zcomp.c @@ -325,12 +325,14 @@ void zcomp_destroy(struct zcomp *comp) * allocate new zcomp and initialize it. return compressing * backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL) * if requested algorithm is not supported, ERR_PTR(-ENOMEM) in - * case of allocation error. + * case of allocation error, or any other error potentially + * returned by functions zcomp_strm_{multi,single}_create. */ struct zcomp *zcomp_create(const char *compress, int max_strm) { struct zcomp *comp; struct zcomp_backend *backend; + int error; backend = find_backend(compress); if (!backend) @@ -342,12 +344,12 @@ struct zcomp *zcomp_create(const char *compress, int max_strm) comp->backend = backend; if (max_strm > 1) - zcomp_strm_multi_create(comp, max_strm); + error = zcomp_strm_multi_create(comp, max_strm); else - zcomp_strm_single_create(comp); - if (!comp->stream) { + error = zcomp_strm_single_create(comp); + if (error) { kfree(comp); - return ERR_PTR(-ENOMEM); + return ERR_PTR(error); } return comp; } |