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| author | Gerald Schaefer <gerald.schaefer@linux.ibm.com> | 2023-08-10 10:22:36 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2023-08-16 15:13:03 +0200 |
| commit | c8f40a0bccefd613748d080147469a4652d6e74c (patch) | |
| tree | 102848fd2fc3d7726abe663dc3ef34c4a5d7cc7e /drivers/s390 | |
| parent | s390/mm: make virt_to_pfn() a static inline (diff) | |
| download | linux-c8f40a0bccefd613748d080147469a4652d6e74c.tar.xz linux-c8f40a0bccefd613748d080147469a4652d6e74c.zip | |
s390/dcssblk: fix kernel crash with list_add corruption
Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk
association") introduced new logic for gendisk association, requiring
drivers to explicitly call dax_add_host() and dax_remove_host().
For dcssblk driver, some dax_remove_host() calls were missing, e.g. in
device remove path. The commit also broke error handling for out_dax case
in device add path, resulting in an extra put_device() w/o the previous
get_device() in that case.
This lead to stale xarray entries after device add / remove cycles. In the
case when a previously used struct gendisk pointer (xarray index) would be
used again, because blk_alloc_disk() happened to return such a pointer, the
xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra
put_device() in the error path. In combination with an already flawed error
handling in dcssblk (device_register() cleanup), which needs to be
addressed in a separate patch, this resulted in a missing device_del() /
klist_del(), and eventually in the kernel crash with list_add corruption on
a subsequent device_add() / klist_add().
Fix this by adding the missing dax_remove_host() calls, and also move the
put_device() in the error path to restore the previous logic.
Fixes: fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk association")
Cc: <stable@vger.kernel.org> # 5.17+
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/block/dcssblk.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 6eafd0a34483..06bcb6c78909 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -412,6 +412,7 @@ removeseg: } list_del(&dev_info->lh); + dax_remove_host(dev_info->gd); kill_dax(dev_info->dax_dev); put_dax(dev_info->dax_dev); del_gendisk(dev_info->gd); @@ -707,9 +708,9 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char goto out; out_dax_host: + put_device(&dev_info->dev); dax_remove_host(dev_info->gd); out_dax: - put_device(&dev_info->dev); kill_dax(dev_info->dax_dev); put_dax(dev_info->dax_dev); put_dev: @@ -789,6 +790,7 @@ dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const ch } list_del(&dev_info->lh); + dax_remove_host(dev_info->gd); kill_dax(dev_info->dax_dev); put_dax(dev_info->dax_dev); del_gendisk(dev_info->gd); |