Messages in this thread Patch in this message | | | From | Guo Chao <> | Subject | [PATCH 6/7] loopdev: remove an user triggable oops | Date | Fri, 25 Jan 2013 18:56:21 +0800 |
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When loopdev is built as module and we pass an invalid parameter, loop_init() will return directly without deregister misc device, which will cause an oops when insert loop module next time because we left some garbage in the misc device list.
Test case: sudo modprobe loop max_part=1024 (failed due to invalid parameter) sudo modprobe loop (oops)
Clean up nicely to avoid such oops.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> --- drivers/block/loop.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 6579f69..9190a82 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1844,11 +1844,15 @@ static int __init loop_init(void) max_part = (1UL << part_shift) - 1; } - if ((1UL << part_shift) > DISK_MAX_PARTS) - return -EINVAL; + if ((1UL << part_shift) > DISK_MAX_PARTS) { + err = -EINVAL; + goto misc_out; + } - if (max_loop > 1UL << (MINORBITS - part_shift)) - return -EINVAL; + if (max_loop > 1UL << (MINORBITS - part_shift)) { + err = -EINVAL; + goto misc_out; + } /* * If max_loop is specified, create that many devices upfront. @@ -1866,8 +1870,10 @@ static int __init loop_init(void) range = 1UL << MINORBITS; } - if (register_blkdev(LOOP_MAJOR, "loop")) - return -EIO; + if (register_blkdev(LOOP_MAJOR, "loop")) { + err = -EIO; + goto misc_out; + } blk_register_region(MKDEV(LOOP_MAJOR, 0), range, THIS_MODULE, loop_probe, NULL, NULL); @@ -1880,6 +1886,10 @@ static int __init loop_init(void) printk(KERN_INFO "loop: module loaded\n"); return 0; + +misc_out: + misc_deregister(&loop_misc); + return err; } static int loop_exit_cb(int id, void *ptr, void *data) -- 1.7.9.5
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