linux/security/keys
Vasily Averin 86d32f9a7c keys: Fix proc_keys_next to increase position index
If seq_file .next function does not change position index,
read after some lseek can generate unexpected output:

    $ dd if=/proc/keys bs=1  # full usual output
    0f6bfdf5 I--Q---     2 perm 3f010000  1000  1000 user      4af2f79ab8848d0a: 740
    1fb91b32 I--Q---     3 perm 1f3f0000  1000 65534 keyring   _uid.1000: 2
    27589480 I--Q---     1 perm 0b0b0000     0     0 user      invocation_id: 16
    2f33ab67 I--Q---   152 perm 3f030000     0     0 keyring   _ses: 2
    33f1d8fa I--Q---     4 perm 3f030000  1000  1000 keyring   _ses: 1
    3d427fda I--Q---     2 perm 3f010000  1000  1000 user      69ec44aec7678e5a: 740
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    521+0 records in
    521+0 records out
    521 bytes copied, 0,00123769 s, 421 kB/s

But a read after lseek in middle of last line results in the partial
last line and then a repeat of the final line:

    $ dd if=/proc/keys bs=500 skip=1
    dd: /proc/keys: cannot skip to specified offset
    g   _uid_ses.1000: 1
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    97 bytes copied, 0,000135035 s, 718 kB/s

and a read after lseek beyond end of file results in the last line being
shown:

    $ dd if=/proc/keys bs=1000 skip=1   # read after lseek beyond end of file
    dd: /proc/keys: cannot skip to specified offset
    3ead4096 I--Q---     1 perm 1f3f0000  1000 65534 keyring   _uid_ses.1000: 1
    0+1 records in
    0+1 records out
    76 bytes copied, 0,000119981 s, 633 kB/s

See https://bugzilla.kernel.org/show_bug.cgi?id=206283

Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-16 10:10:50 -07:00
..
encrypted-keys KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
trusted-keys KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
big_key.c KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
compat_dh.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
compat.c KEYS: remove CONFIG_KEYS_COMPAT 2019-12-12 23:41:17 +02:00
dh.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
gc.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
internal.h KEYS: Avoid false positive ENOMEM error on key read 2020-03-29 12:40:41 +01:00
Kconfig KEYS: remove CONFIG_KEYS_COMPAT 2019-12-12 23:41:17 +02:00
key.c KEYS: reaching the keys quotas correctly 2020-03-15 20:59:50 +02:00
keyctl_pkey.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
keyctl.c Keyrings fixes 2020-04-04 12:24:47 -07:00
keyring.c KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
Makefile KEYS: remove CONFIG_KEYS_COMPAT 2019-12-12 23:41:17 +02:00
permission.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
persistent.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
proc.c keys: Fix proc_keys_next to increase position index 2020-04-16 10:10:50 -07:00
process_keys.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
request_key_auth.c KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
request_key.c keys: ensure that ->match_free() is called in request_key_and_link() 2019-08-30 11:10:55 -07:00
sysctl.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
user_defined.c KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00