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author | 2022-10-11 14:38:38 -0700 | |
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committer | 2022-10-19 20:54:43 -0700 | |
commit | ccd30a476f8e864732de220bd50e6f372f5ebcab (patch) | |
tree | f5a57819df1068b8d13c5a897bb2b94b47890466 /fs/crypto/keyring.c | |
parent | Linux 6.1-rc1 (diff) | |
download | linux-ccd30a476f8e864732de220bd50e6f372f5ebcab.tar.gz linux-ccd30a476f8e864732de220bd50e6f372f5ebcab.tar.bz2 linux-ccd30a476f8e864732de220bd50e6f372f5ebcab.zip |
fscrypt: fix keyring memory leak on mount failure
Commit d7e7b9af104c ("fscrypt: stop using keyrings subsystem for
fscrypt_master_key") moved the keyring destruction from __put_super() to
generic_shutdown_super() so that the filesystem's block device(s) are
still available. Unfortunately, this causes a memory leak in the case
where a mount is attempted with the test_dummy_encryption mount option,
but the mount fails after the option has already been processed.
To fix this, attempt the keyring destruction in both places.
Reported-by: syzbot+104c2a89561289cec13e@syzkaller.appspotmail.com
Fixes: d7e7b9af104c ("fscrypt: stop using keyrings subsystem for fscrypt_master_key")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Link: https://lore.kernel.org/r/20221011213838.209879-1-ebiggers@kernel.org
Diffstat (limited to 'fs/crypto/keyring.c')
-rw-r--r-- | fs/crypto/keyring.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c index 1cca09aa43f8..2a24b1f0ae68 100644 --- a/fs/crypto/keyring.c +++ b/fs/crypto/keyring.c @@ -205,14 +205,19 @@ static int allocate_filesystem_keyring(struct super_block *sb) } /* - * This is called at unmount time to release all encryption keys that have been - * added to the filesystem, along with the keyring that contains them. + * Release all encryption keys that have been added to the filesystem, along + * with the keyring that contains them. * - * Note that besides clearing and freeing memory, this might need to evict keys - * from the keyslots of an inline crypto engine. Therefore, this must be called - * while the filesystem's underlying block device(s) are still available. + * This is called at unmount time. The filesystem's underlying block device(s) + * are still available at this time; this is important because after user file + * accesses have been allowed, this function may need to evict keys from the + * keyslots of an inline crypto engine, which requires the block device(s). + * + * This is also called when the super_block is being freed. This is needed to + * avoid a memory leak if mounting fails after the "test_dummy_encryption" + * option was processed, as in that case the unmount-time call isn't made. */ -void fscrypt_sb_delete(struct super_block *sb) +void fscrypt_destroy_keyring(struct super_block *sb) { struct fscrypt_keyring *keyring = sb->s_master_keys; size_t i; |