Kees Cook 8880fa32c5 pstore/ram: Run without kernel crash dump region ... The ram pstore backend has always had the crash dumper frontend enabled unconditionally. However, it was possible to effectively disable it by setting a record_size=0. All the machinery would run (storing dumps to the temporary crash buffer), but 0 bytes would ultimately get stored due to there being no przs allocated for dumps. Commit 89d328f637 ("pstore/ram: Correctly calculate usable PRZ bytes"), however, assumed that there would always be at least one allocated dprz for calculating the size of the temporary crash buffer. This was, of course, not the case when record_size=0, and would lead to a NULL deref trying to find the dprz buffer size: BUG: unable to handle kernel NULL pointer dereference at (null) ... IP: ramoops_probe+0x285/0x37e (fs/pstore/ram.c:808) cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size; Instead, we need to only enable the frontends based on the success of the prz initialization and only take the needed actions when those zones are available. (This also fixes a possible error in detecting if the ftrace frontend should be enabled.) Reported-and-tested-by: Yaro Slav <yaro330@gmail.com> Fixes: 89d328f637 ("pstore/ram: Correctly calculate usable PRZ bytes") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>		2019-05-31 01:19:06 -07:00
..
ftrace.c	pstore: Fix bool initialization/comparison	2018-12-03 16:52:35 -08:00
inode.c	treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively	2019-04-09 14:19:06 +02:00
internal.h	pstore: Centralize init/exit routines	2018-10-22 07:11:58 -07:00
Kconfig	mm: remove CONFIG_HAVE_MEMBLOCK	2018-10-31 08:54:15 -07:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
platform.c	pstore/ram: Run without kernel crash dump region	2019-05-31 01:19:06 -07:00
pmsg.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
ram_core.c	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
ram.c	pstore/ram: Run without kernel crash dump region	2019-05-31 01:19:06 -07:00