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| author | Quentin Casasnovas <quentin.casasnovas@oracle.com> | 2014-11-12 11:19:23 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-21 09:23:06 -0800 |
| commit | 197b3975f4b079f004b02786bfa985ec276f6112 (patch) | |
| tree | 04c27cf3d5db640bfd722ccde48179cc54e2cae5 /drivers | |
| parent | 84efcb2025064ad5650a476b8beab2fb2c27cc9f (diff) | |
| download | lwn-197b3975f4b079f004b02786bfa985ec276f6112.tar.gz lwn-197b3975f4b079f004b02786bfa985ec276f6112.zip | |
regmap: fix kernel hang on regmap_bulk_write with zero val_count.
Fixes commit 2f06fa04cf35da5c24481da3ac84a2900d0b99c3 which was an
incorrect backported version of commit
d6b41cb06044a7d895db82bdd54f6e4219970510 upstream.
If val_count is zero we return -EINVAL with map->lock_arg locked, which
will deadlock the kernel next time we try to acquire this lock.
This was introduced by f5942dd ("regmap: fix possible ZERO_SIZE_PTR pointer
dereferencing error.") which improperly back-ported d6b41cb0.
This issue was found during review of Ubuntu Trusty 3.13.0-40.68 kernel to
prepare Ksplice rebootless updates.
Fixes: f5942dd ("regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error.")
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/regmap/regmap.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index f6cff3be0ed7..2f9a3d8ecbbf 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1557,8 +1557,10 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val, } else { void *wval; - if (!val_count) - return -EINVAL; + if (!val_count) { + ret = -EINVAL; + goto out; + } wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL); if (!wval) { |