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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-09 10:06:24 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-09 10:06:24 -0700 |
commit | d5791d13b1d45542895104edf4b09476d5ad24b0 (patch) | |
tree | 3e3557240717a100dcb63316b4d0c1697e943320 | |
parent | f751aa125d1843ea4a9a264b451fd5b1639fab20 (diff) | |
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Fix invalid access errors in blk_lookup_devt
Commit 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 ("block: do_mounts -
accept root=<non-existant partition>") extended blk_lookup_devt() to be
able to look up partitions that had not yet been registered, but in the
process made the assumption that the '&block_class.devices' list only
contains disk devices and that you can do 'dev_to_disk(dev)' on them.
That isn't actually true. The block_class device list also contains the
partitions we've discovered so far, and you can't just do a
'dev_to_disk()' on those.
So make sure to only work on devices that block/genhd.c has registered
itself, something we can test by checking the 'dev->type' member. This
makes the loop in blk_lookup_devt() match the other such loops in this
file.
[ We may want to do an alternate version that knows to handle _either_
whole-disk devices or partitions, but for now this is the minimal fix
for a series of crashes reported by Mariusz Kozlowski in
http://lkml.org/lkml/2008/5/25/25
and Ingo in
http://lkml.org/lkml/2008/6/9/39 ]
Reported-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Neil Brown <neilb@suse.de>
Cc: Joao Luis Meloni Assirati <assirati@nonada.if.usp.br>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | block/genhd.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/block/genhd.c b/block/genhd.c index 129ad93..b922d48 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -660,6 +660,8 @@ dev_t blk_lookup_devt(const char *name, int part) mutex_lock(&block_class_lock); list_for_each_entry(dev, &block_class.devices, node) { + if (dev->type != &disk_type) + continue; if (strcmp(dev->bus_id, name) == 0) { struct gendisk *disk = dev_to_disk(dev); |