0daf3b0fe4
commit bb6cc253861bd5a7cf8439e2118659696df9619f upstream.
Commit 028ddcac477b ("bcache: Remove unnecessary NULL point check in
node allocations") replaced IS_ERR_OR_NULL by IS_ERR. This leads to a
NULL pointer dereference.
BUG: kernel NULL pointer dereference, address: 0000000000000080
Call Trace:
? __die_body.cold+0x1a/0x1f
? page_fault_oops+0xd2/0x2b0
? exc_page_fault+0x70/0x170
? asm_exc_page_fault+0x22/0x30
? btree_node_free+0xf/0x160 [bcache]
? up_write+0x32/0x60
btree_gc_coalesce+0x2aa/0x890 [bcache]
? bch_extent_bad+0x70/0x170 [bcache]
btree_gc_recurse+0x130/0x390 [bcache]
? btree_gc_mark_node+0x72/0x230 [bcache]
bch_btree_gc+0x5da/0x600 [bcache]
? cpuusage_read+0x10/0x10
? bch_btree_gc+0x600/0x600 [bcache]
bch_gc_thread+0x135/0x180 [bcache]
The relevant code starts with:
new_nodes[0] = NULL;
for (i = 0; i < nodes; i++) {
if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key)))
goto out_nocoalesce;
// ...
out_nocoalesce:
// ...
for (i = 0; i < nodes; i++)
if (!IS_ERR(new_nodes[i])) { // IS_ERR_OR_NULL before
028ddcac477b
btree_node_free(new_nodes[i]); // new_nodes[0] is NULL
rw_unlock(true, new_nodes[i]);
}
This patch replaces IS_ERR() by IS_ERR_OR_NULL() to fix this.
Fixes: 028ddcac477b ("bcache: Remove unnecessary NULL point check in node allocations")
Link: https://lore.kernel.org/all/3DF4A87A-2AC1-4893-AE5F-E921478419A9@suse.de/
Cc: stable@vger.kernel.org
Cc: Zheng Wang <zyytlz.wz@163.com>
Cc: Coly Li <colyli@suse.de>
Signed-off-by: Markus Weippert <markus@gekmihesg.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.