| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.15 01/72] fscache_cookie_enabled: check cookie is valid before accessing it | Date | Mon, 10 Jan 2022 08:22:38 +0100 |
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From: Dominique Martinet <asmadeus@codewreck.org>
commit 0dc54bd4d6e03be1f0b678c4297170b79f1a44ab upstream.
fscache_cookie_enabled() could be called on NULL cookies and cause a null pointer dereference when accessing cookie flags: just make sure the cookie is valid first
Suggested-by: David Howells <dhowells@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Cc: Jeffrey E Altman <jaltman@auristor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/linux/fscache.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/fscache.h +++ b/include/linux/fscache.h @@ -167,7 +167,7 @@ struct fscache_cookie { static inline bool fscache_cookie_enabled(struct fscache_cookie *cookie) { - return test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); + return fscache_cookie_valid(cookie) && test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags); } /*
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