linux/drivers/md, branch v3.2.38

dm ioctl: prevent unsafe change to dm_ioctl data_size

2013-01-03T03:33:47Z

commit e910d7ebecd1aac43125944a8641b6cb1a0dfabe upstream. Abort dm ioctl processing if userspace changes the data_size parameter after we validated it but before we finished copying the data buffer from userspace. The dm ioctl parameters are processed in the following sequence: 1. ctl_ioctl() calls copy_params(); 2. copy_params() makes a first copy of the fixed-sized portion of the userspace parameters into the local variable "tmp"; 3. copy_params() then validates tmp.data_size and allocates a new structure big enough to hold the complete data and copies the whole userspace buffer there; 4. ctl_ioctl() reads userspace data the second time and copies the whole buffer into the pointer "param"; 5. ctl_ioctl() reads param->data_size without any validation and stores it in the variable "input_param_size"; 6. "input_param_size" is further used as the authoritative size of the kernel buffer. The problem is that userspace code could change the contents of user memory between steps 2 and 4. In particular, the data_size parameter can be changed to an invalid value after the kernel has validated it. This lets userspace force the kernel to access invalid kernel memory. The fix is to ensure that the size has not changed at step 4. This patch shouldn't have a security impact because CAP_SYS_ADMIN is required to run this code, but it should be fixed anyway. Reported-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Signed-off-by: Ben Hutchings

dm persistent data: rename node to btree_node

2013-01-03T03:33:46Z

commit 550929faf89e2e2cdb3e9945ea87d383989274cf upstream. This patch fixes a compilation failure on sparc32 by renaming struct node. struct node is already defined in include/linux/node.h. On sparc32, it happens to be included through other dependencies and persistent-data doesn't compile because of conflicting declarations. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

dm: fix deadlock with request based dm and queue request_fn recursion

2012-12-06T11:20:34Z

commit a8c32a5c98943d370ea606a2e7dc04717eb92206 upstream. Request based dm attempts to re-run the request queue off the request completion path. If used with a driver that potentially does end_io from its request_fn, we could deadlock trying to recurse back into request dispatch. Fix this by punting the request queue run to kblockd. Tested to fix a quickly reproducible deadlock in such a scenario. Acked-by: Alasdair G Kergon Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings

md: Avoid write invalid address if read_seqretry returned true.

2012-12-06T11:20:29Z

commit 35f9ac2dcec8f79d7059ce174fd7b7ee3290d620 upstream. If read_seqretry returned true and bbp was changed, it will write invalid address which can cause some serious problem. This bug was introduced by commit v3.0-rc7-130-g2699b67. So fix is suitable for 3.0.y thru 3.6.y. Reported-by: zhuwenfeng@kedacom.com Tested-by: zhuwenfeng@kedacom.com Signed-off-by: Jianpeng Ma Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings

md: Reassigned the parameters if read_seqretry returned true in func md_is_badblock.

2012-12-06T11:20:28Z

commit ab05613a0646dcc11049692d54bae76ca9ffa910 upstream. This bug was introduced by commit(v3.0-rc7-126-g2230dfe). So fix is suitable for 3.0.y thru 3.6.y. Signed-off-by: Jianpeng Ma Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings

md/raid10: use correct limit variable

2012-10-30T23:26:43Z

commit 91502f099dfc5a1e8812898e26ee280713e1d002 upstream. Clang complains that we are assigning a variable to itself. This should be using bad_sectors like the similar earlier check does. Bug has been present since 3.1-rc1. It is minor but could conceivably cause corruption or other bad behaviour. Signed-off-by: Dan Carpenter Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings

md/raid10: fix "enough" function for detecting if array is failed.

2012-10-10T02:31:06Z

commit 80b4812407c6b1f66a4f2430e69747a13f010839 upstream. The 'enough' function is written to work with 'near' arrays only in that is implicitly assumes that the offset from one 'group' of devices to the next is the same as the number of copies. In reality it is the number of 'near' copies. So change it to make this number explicit. This bug makes it possible to run arrays without enough drives present, which is dangerous. It is appropriate for an -stable kernel, but will almost certainly need to be modified for some of them. Reported-by: Jakub Husák Signed-off-by: NeilBrown [bwh: Backported to 3.2: s/geo->/conf->/] Signed-off-by: Ben Hutchings

dm table: clear add_random unless all devices have it set

2012-10-10T02:31:06Z

commit c3c4555edd10dbc0b388a0125b9c50de5e79af05 upstream. Always clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not have it set. Otherwise devices with predictable characteristics may contribute entropy. QUEUE_FLAG_ADD_RANDOM specifies whether or not queue IO timings contribute to the random pool. For bio-based targets this flag is always 0 because such devices have no real queue. For request-based devices this flag was always set to 1 by default. Now set it according to the flags on underlying devices. If there is at least one device which should not contribute, set the flag to zero: If a device, such as fast SSD storage, is not suitable for supplying entropy, a request-based queue stacked over it will not be either. Because the checking logic is exactly same as for the rotational flag, share the iteration function with device_is_nonrot(). Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon Signed-off-by: Ben Hutchings

dm: handle requests beyond end of device instead of using BUG_ON

2012-10-10T02:31:05Z

commit ba1cbad93dd47223b1f3b8edd50dd9ef2abcb2ed upstream. The access beyond the end of device BUG_ON that was introduced to dm_request_fn via commit 29e4013de7ad950280e4b2208 ("dm: implement REQ_FLUSH/FUA support for request-based dm") was an overly drastic (but simple) response to this situation. I have received a report that this BUG_ON was hit and now think it would be better to use dm_kill_unmapped_request() to fail the clone and original request with -EIO. map_request() will assign the valid target returned by dm_table_find_target to tio->ti. But when the target isn't valid tio->ti is never assigned (because map_request isn't called); so add a check for tio->ti != NULL to dm_done(). Reported-by: Mike Christie Signed-off-by: Mike Snitzer Signed-off-by: Jun'ichi Nomura Signed-off-by: Alasdair G Kergon Signed-off-by: Ben Hutchings

md: Don't truncate size at 4TB for RAID0 and Linear

2012-09-12T02:37:05Z

commit 667a5313ecd7308d79629c0738b0db588b0b0a4e upstream. commit 27a7b260f71439c40546b43588448faac01adb93 md: Fix handling for devices from 2TB to 4TB in 0.90 metadata. changed 0.90 metadata handling to truncated size to 4TB as that is all that 0.90 can record. However for RAID0 and Linear, 0.90 doesn't need to record the size, so this truncation is not needed and causes working arrays to become too small. So avoid the truncation for RAID0 and Linear This bug was introduced in 3.1 and is suitable for any stable kernels from then onwards. As the offending commit was tagged for 'stable', any stable kernel that it was applied to should also get this patch. That includes at least 2.6.32, 2.6.33 and 3.0. (Thanks to Ben Hutchings for providing that list). Signed-off-by: Neil Brown Signed-off-by: Ben Hutchings