linux.git/fs/pstore, branch v5.4.64

pstore: Fix linking when crypto API disabled

2020-08-19T06:16:27+00:00

commit fd49e03280e596e54edb93a91bc96170f8e97e4a upstream.

When building a kernel with CONFIG_PSTORE=y and CONFIG_CRYPTO not set,
a build error happens:

    ld: fs/pstore/platform.o: in function `pstore_dump':
    platform.c:(.text+0x3f9): undefined reference to `crypto_comp_compress'
    ld: fs/pstore/platform.o: in function `pstore_get_backend_records':
    platform.c:(.text+0x784): undefined reference to `crypto_comp_decompress'

This because some pstore code uses crypto_comp_(de)compress regardless
of the CONFIG_CRYPTO status. Fix it by wrapping the (de)compress usage
by IS_ENABLED(CONFIG_PSTORE_COMPRESS)

Signed-off-by: Matteo Croce 
Link: https://lore.kernel.org/lkml/20200706234045.9516-1-mcroce@linux.microsoft.com
Fixes: cb3bee0369bc ("pstore: Use crypto compress API")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore: pstore_ftrace_seq_next should increase position index

2020-04-17T08:50:12+00:00

commit 6c871b7314dde9ab64f20de8f5aa3d01be4518e8 upstream.

In Aug 2018 NeilBrown noticed
commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface")
"Some ->next functions do not increment *pos when they return NULL...
Note that such ->next functions are buggy and should be fixed.
A simple demonstration is

 dd if=/proc/swaps bs=1000 skip=1

Choose any block size larger than the size of /proc/swaps. This will
always show the whole last line of /proc/swaps"

/proc/swaps output was fixed recently, however there are lot of other
affected files, and one of them is related to pstore subsystem.

If .next function does not change position index, following .show function
will repeat output related to current position index.

There are at least 2 related problems:
- read after lseek beyond end of file, described above by NeilBrown
  "dd if= bs=1000 skip=1" will generate whole last list
- read after lseek on in middle of last line will output expected rest of
  last line but then repeat whole last line once again.

If .show() function generates multy-line output (like
pstore_ftrace_seq_show() does ?) following bash script cycles endlessly

 $ q=;while read -r r;do echo "$((++q)) $r";done < AFFECTED_FILE

Unfortunately I'm not familiar enough to pstore subsystem and was unable
to find affected pstore-related file on my test node.

If .next function does not change position index, following .show function
will repeat output related to current position index.

Cc: stable@vger.kernel.org
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin 
Link: https://lore.kernel.org/r/4e49830d-4c88-0171-ee24-1ee540028dad@virtuozzo.com
[kees: with robustness tweak from Joel Fernandes ]
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore/platform: fix potential mem leak if pstore_init_fs failed

2020-04-17T08:50:03+00:00

[ Upstream commit 8a57d6d4ddfa41c49014e20493152c41a38fcbf8 ]

There is a potential mem leak when pstore_init_fs failed,
since the pstore compression maybe unlikey to initialized
successfully. We must clean up the allocation once this
unlikey issue happens.

Signed-off-by: chenqiwu 
Link: https://lore.kernel.org/r/1581068800-13817-1-git-send-email-qiwuchen55@gmail.com
Signed-off-by: Kees Cook 
Signed-off-by: Sasha Levin

pstore/ram: Regularize prz label allocation lifetime

2020-01-14T19:08:28+00:00

commit e163fdb3f7f8c62dccf194f3f37a7bcb3c333aa8 upstream.

In my attempt to fix a memory leak, I introduced a double-free in the
pstore error path. Instead of trying to manage the allocation lifetime
between persistent_ram_new() and its callers, adjust the logic so
persistent_ram_new() always takes a kstrdup() copy, and leaves the
caller's allocation lifetime up to the caller. Therefore callers are
_always_ responsible for freeing their label. Before, it only needed
freeing when the prz itself failed to allocate, and not in any of the
other prz failure cases, which callers would have no visibility into,
which is the root design problem that lead to both the leak and now
double-free bugs.

Reported-by: Cengiz Can 
Link: https://lore.kernel.org/lkml/d4ec59002ede4aaf9928c7f7526da87c@kernel.wtf
Fixes: 8df955a32a73 ("pstore/ram: Fix error-path memory leak in persistent_ram_new() callers")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore/ram: Fix error-path memory leak in persistent_ram_new() callers

2020-01-09T09:19:57+00:00

commit 8df955a32a73315055e0cd187cbb1cea5820394b upstream.

For callers that allocated a label for persistent_ram_new(), if the call
fails, they must clean up the allocation.

Suggested-by: Navid Emamdoost 
Fixes: 1227daa43bce ("pstore/ram: Clarify resource reservation labels")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20191211191353.14385-1-navid.emamdoost@gmail.com
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore/ram: Write new dumps to start of recycled zones

2020-01-09T09:19:57+00:00

commit 9e5f1c19800b808a37fb9815a26d382132c26c3d upstream.

The ram_core.c routines treat przs as circular buffers. When writing a
new crash dump, the old buffer needs to be cleared so that the new dump
doesn't end up in the wrong place (i.e. at the end).

The solution to this problem is to reset the circular buffer state before
writing a new Oops dump.

Signed-off-by: Aleksandr Yashkin 
Signed-off-by: Nikolay Merinov 
Signed-off-by: Ariel Gilman 
Link: https://lore.kernel.org/r/20191223133816.28155-1-n.merinov@inango-systems.com
Fixes: 896fc1f0c4c6 ("pstore/ram: Switch to persistent_ram routines")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore: fs superblock limits

2019-08-30T15:11:25+00:00

Leaving granularity at 1ns because it is dependent on the specific
attached backing pstore module. ramoops has microsecond resolution.

Fix the readback of ramoops fractional timestamp microseconds,
which has incorrectly been reporting the value as nanoseconds.

Fixes: 3f8f80f0cfeb ("pstore/ram: Read and write to the 'compressed' flag of pstore").

Signed-off-by: Deepa Dinamani 
Acked-by: Kees Cook 
Acked-by: Jeff Layton 
Cc: anton@enomsg.org
Cc: ccross@android.com
Cc: keescook@chromium.org
Cc: tony.luck@intel.com

pstore: Fix double-free in pstore_mkfile() failure path

2019-07-09T04:04:42+00:00

The pstore_mkfile() function is passed a pointer to a struct
pstore_record. On success it consumes this 'record' pointer and
references it from the created inode.

On failure, however, it may or may not free the record. There are even
two different code paths which return -ENOMEM -- one of which does and
the other doesn't free the record.

Make the behaviour deterministic by never consuming and freeing the
record when returning failure, allowing the caller to do the cleanup
consistently.

Signed-off-by: Norbert Manthey 
Link: https://lore.kernel.org/r/1562331960-26198-1-git-send-email-nmanthey@amazon.de
Fixes: 83f70f0769ddd ("pstore: Do not duplicate record metadata")
Fixes: 1dfff7dd67d1a ("pstore: Pass record contents instead of copying")
Cc: stable@vger.kernel.org
[kees: also move "private" allocation location, rename inode cleanup label]
Signed-off-by: Kees Cook

pstore: no need to check return value of debugfs_create functions

2019-07-09T04:04:42+00:00

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Kees Cook 
Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Tony Luck 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Kees Cook

pstore/ram: Improve backward compatibility with older Chromebooks

2019-07-09T04:04:42+00:00

When you try to run an upstream kernel on an old ARM-based Chromebook
you'll find that console-ramoops doesn't work.

Old ARM-based Chromebooks, before 
("ramoops: support upstream {console,pmsg,ftrace}-size properties")
used to create a "ramoops" node at the top level that looked like:

/ {
  ramoops {
    compatible = "ramoops";
    reg = <...>;
    record-size = <...>;
    dump-oops;
  };
};

...and these Chromebooks assumed that the downstream kernel would make
console_size / pmsg_size match the record size.  The above ramoops
node was added by the firmware so it's not easy to make any changes.

Let's match the expected behavior, but only for those using the old
backward-compatible way of working where ramoops is right under the
root node.

NOTE: if there are some out-of-tree devices that had ramoops at the
top level, left everything but the record size as 0, and somehow
doesn't want this behavior, we can try to add more conditions here.

Signed-off-by: Douglas Anderson 
Signed-off-by: Kees Cook