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.
Fixes: beca3ec71f
("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>
This commit is contained in:
parent
72714841b7
commit
3aaf14da80
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@ -330,12 +330,14 @@ void zcomp_destroy(struct zcomp *comp)
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* allocate new zcomp and initialize it. return compressing
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* backend pointer or ERR_PTR if things went bad. ERR_PTR(-EINVAL)
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* if requested algorithm is not supported, ERR_PTR(-ENOMEM) in
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* case of allocation error.
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* case of allocation error, or any other error potentially
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* returned by functions zcomp_strm_{multi,single}_create.
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*/
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struct zcomp *zcomp_create(const char *compress, int max_strm)
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{
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struct zcomp *comp;
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struct zcomp_backend *backend;
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int error;
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backend = find_backend(compress);
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if (!backend)
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@ -347,12 +349,12 @@ struct zcomp *zcomp_create(const char *compress, int max_strm)
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comp->backend = backend;
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if (max_strm > 1)
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zcomp_strm_multi_create(comp, max_strm);
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error = zcomp_strm_multi_create(comp, max_strm);
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else
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zcomp_strm_single_create(comp);
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if (!comp->stream) {
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error = zcomp_strm_single_create(comp);
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if (error) {
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kfree(comp);
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return ERR_PTR(-ENOMEM);
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return ERR_PTR(error);
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}
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return comp;
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}
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