5.15-stable review patch. If anyone has any objections, please let me know.
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From: Kory Maincent kory.maincent@bootlin.com
[ Upstream commit 108a36d07c01edbc5942d27c92494d1c6e4d45a0 ]
A bitset without mask in a _SET request means we want exactly the bits in the bitset to be set. This works correctly for compact format but when verbose format is parsed, ethnl_update_bitset32_verbose() only sets the bits present in the request bitset but does not clear the rest. The commit 6699170376ab fixes this issue by clearing the whole target bitmap before we start iterating. The solution proposed brought an issue with the behavior of the mod variable. As the bitset is always cleared the old val will always differ to the new val.
Fix it by adding a new temporary variable which save the state of the old bitmap.
Fixes: 6699170376ab ("ethtool: fix application of verbose no_mask bitset") Signed-off-by: Kory Maincent kory.maincent@bootlin.com Reviewed-by: Simon Horman horms@kernel.org Link: https://lore.kernel.org/r/20231009133645.44503-1-kory.maincent@bootlin.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ethtool/bitset.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c index 0515d6604b3b9..883ed9be81f9f 100644 --- a/net/ethtool/bitset.c +++ b/net/ethtool/bitset.c @@ -431,8 +431,10 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, ethnl_string_array_t names, struct netlink_ext_ack *extack, bool *mod) { + u32 *orig_bitmap, *saved_bitmap = NULL; struct nlattr *bit_attr; bool no_mask; + bool dummy; int rem; int ret;
@@ -448,8 +450,22 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, }
no_mask = tb[ETHTOOL_A_BITSET_NOMASK]; - if (no_mask) - ethnl_bitmap32_clear(bitmap, 0, nbits, mod); + if (no_mask) { + unsigned int nwords = DIV_ROUND_UP(nbits, 32); + unsigned int nbytes = nwords * sizeof(u32); + + /* The bitmap size is only the size of the map part without + * its mask part. + */ + saved_bitmap = kcalloc(nwords, sizeof(u32), GFP_KERNEL); + if (!saved_bitmap) + return -ENOMEM; + memcpy(saved_bitmap, bitmap, nbytes); + ethnl_bitmap32_clear(bitmap, 0, nbits, &dummy); + orig_bitmap = saved_bitmap; + } else { + orig_bitmap = bitmap; + }
nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) { bool old_val, new_val; @@ -458,13 +474,14 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, if (nla_type(bit_attr) != ETHTOOL_A_BITSET_BITS_BIT) { NL_SET_ERR_MSG_ATTR(extack, bit_attr, "only ETHTOOL_A_BITSET_BITS_BIT allowed in ETHTOOL_A_BITSET_BITS"); - return -EINVAL; + ret = -EINVAL; + goto out; } ret = ethnl_parse_bit(&idx, &new_val, nbits, bit_attr, no_mask, names, extack); if (ret < 0) - return ret; - old_val = bitmap[idx / 32] & ((u32)1 << (idx % 32)); + goto out; + old_val = orig_bitmap[idx / 32] & ((u32)1 << (idx % 32)); if (new_val != old_val) { if (new_val) bitmap[idx / 32] |= ((u32)1 << (idx % 32)); @@ -474,7 +491,10 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits, } }
- return 0; + ret = 0; +out: + kfree(saved_bitmap); + return ret; }
static int ethnl_compact_sanity_checks(unsigned int nbits,