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| author | Jakub Kicinski <kuba@kernel.org> | 2026-08-12 09:22:30 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-13 17:44:54 -0700 |
| commit | 77e80af7d2d4dc223716c90e9fc043bc66a8335f (patch) | |
| tree | 12776391d429fbe7f318a8d5852152f6c24bd9f3 | |
| parent | a7c44619c6977fd64da99a6d1c2b73e2ad9af873 (diff) | |
| download | linux-77e80af7d2d4dc223716c90e9fc043bc66a8335f.tar.gz linux-77e80af7d2d4dc223716c90e9fc043bc66a8335f.zip | |
ethtool: tsconfig: reject zero-valued tx_type and rx_filter bitsets
The ffs()/fls() guard in ethnl_set_tsconfig() was meant to enforce
that the user selects exactly one tx_type (and one rx_filter)
at a time (off / none are explicit types with non-zero values).
However, both ffs(0) and fls(0) return 0, so the guard passes
a zero-valued bitset through.
The subsequent ffs(req_tx_type) - 1 would produce -1, if user selected
no bit. net_hwtstamp_validate() catches the invalid -1 downstream,
but returns a generic error (-ERANGE) without telling the user
what went wrong. Return -EINVAL + extack instead.
Replace the ffs()/fls() comparison with a hweight32() == 1 check.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Joe Damato <joe@dama.to>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260812162230.1837788-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ethtool/tsconfig.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/net/ethtool/tsconfig.c b/net/ethtool/tsconfig.c index 24b64862011f..6be3aa5d4bc1 100644 --- a/net/ethtool/tsconfig.c +++ b/net/ethtool/tsconfig.c @@ -359,8 +359,10 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base, if (ret < 0) goto err_free_hwprov; - /* Select only one tx type at a time */ - if (ffs(req_tx_type) != fls(req_tx_type)) { + /* Select exactly one tx type at a time */ + if (hweight32(req_tx_type) != 1) { + NL_SET_BAD_ATTR(info->extack, + tb[ETHTOOL_A_TSCONFIG_TX_TYPES]); ret = -EINVAL; goto err_free_hwprov; } @@ -380,8 +382,10 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base, if (ret < 0) goto err_free_hwprov; - /* Select only one rx filter at a time */ - if (ffs(req_rx_filter) != fls(req_rx_filter)) { + /* Select exactly one rx filter at a time */ + if (hweight32(req_rx_filter) != 1) { + NL_SET_BAD_ATTR(info->extack, + tb[ETHTOOL_A_TSCONFIG_RX_FILTERS]); ret = -EINVAL; goto err_free_hwprov; } |