linux/drivers/android
Jann Horn 2a9edd056e binder: Handle start==NULL in binder_update_page_range()
The old loop wouldn't stop when reaching `start` if `start==NULL`, instead
continuing backwards to index -1 and crashing.

Luckily you need to be highly privileged to map things at NULL, so it's not
a big problem.

Fix it by adjusting the loop so that the loop variable is always in bounds.

This patch is deliberately minimal to simplify backporting, but IMO this
function could use a refactor. The jump labels in the second loop body are
horrible (the error gotos should be jumping to free_range instead), and
both loops would look nicer if they just iterated upwards through indices.
And the up_read()+mmput() shouldn't be duplicated like that.

Cc: stable@vger.kernel.org
Fixes: 457b9a6f09 ("Staging: android: add binder driver")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20191018205631.248274-3-jannh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-14 11:44:47 +08:00
..
binder_alloc_selftest.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
binder_alloc.c binder: Handle start==NULL in binder_update_page_range() 2019-11-14 11:44:47 +08:00
binder_alloc.h binder: return errors from buffer copy functions 2019-07-01 08:42:47 +02:00
binder_internal.h binder: prevent UAF read in print_binder_transaction_log_entry() 2019-10-10 14:39:22 +02:00
binder_trace.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282 2019-06-05 17:36:37 +02:00
binder.c Merge 5.4-rc5 into char-misc-next 2019-10-27 18:48:33 +01:00
binderfs.c binder: Add binder_proc logging to binderfs 2019-09-04 13:31:26 +02:00
Kconfig binder: add functions to copy to/from binder buffers 2019-02-12 10:43:57 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00