Eric Biggers 03a573da47 FS-Cache: fix dereference of NULL user_key_payload ... commit d124b2c53c7bee6569d2a2d0b18b4a1afde00134 upstream. When the file /proc/fs/fscache/objects (available with CONFIG_FSCACHE_OBJECT_LIST=y) is opened, we request a user key with description "fscache:objlist", then access its payload. However, a revoked key has a NULL payload, and we failed to check for this. request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we access its payload. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. Fixes: 4fbf4291aa ("FS-Cache: Allow the current state of all objects to be dumped") Reviewed-by: James Morris <james.l.morris@oracle.com> Cc: <stable@vger.kernel.org> [v2.6.32+] Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Willy Tarreau <w@1wt.eu>		2019-07-27 21:44:20 +02:00
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cache.c
cookie.c
fsdef.c
histogram.c
internal.h
Kconfig
main.c
Makefile
netfs.c
object-list.c
object.c
operation.c
page.c
proc.c
stats.c