From nobody Mon Feb 9 07:19:41 2026 Received: from out-184.mta1.migadu.com (out-184.mta1.migadu.com [95.215.58.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 05E82183CC5 for ; Thu, 1 Aug 2024 13:20:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722518410; cv=none; b=kkiN9WAWQQ5wTC6sCZISj4Jc70D5TGPBgj3zdJvTFcnCiq4W6Brcel4CBWMMRmxBlzSxco4tNALN1R2SMj/Dlgll5uOnUgepqQBcAkE/8btYPuzaaoXE5flISNG/M84mXXf2g7f11BKsm1khzePXWbl3U6Uu/eVSRdHENbxEjlY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722518410; c=relaxed/simple; bh=hYi7Em6xyMqmYJw3uVKzeS2OkCvSGj+g6fuB3Bg9S68=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=szGepvJopwN4BuvzBqtPaCxUlCBTDx4gP5hzBmvVYaXgLeU6xufdLNqPdhhkz0mCb3OQQY/ZX9UCGJkhACM/xppZJ0kHSApEM+R2qs0n9kXkcOmyJcMtfke2NlGS/aF+VOB5wNYPvKcFX2H0it2eUsIdJKZqyLY2xOdqm2cn4ME= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=g70M3ndL; arc=none smtp.client-ip=95.215.58.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="g70M3ndL" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1722518406; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=hv4THZ171etWiuRAMHtpZz9WOVnqDt4/Ch3TvuhHnmA=; b=g70M3ndLDmJWQAibofN17vhIXw3TjWi1zTGYg4kC2x5My57t/NlT2KWULtWIx+ikhvtWi4 AfeSOScVQyBfm0fMLIBAttzlQIotW7KnLpEEePxiLt86RWXFNvfDcTDgb7VjIHeIbFI5aA owTjaXYq6LBalZoC3jJ5hgwhaGWm2XI= From: Wen Yang To: "Eric W . Biederman" , Luis Chamberlain , Kees Cook , Joel Granados , Christian Brauner Cc: Wen Yang , Dave Young , linux-kernel@vger.kernel.org Subject: [PATCH v3] sysctl: simplify the min/max boundary check Date: Thu, 1 Aug 2024 21:19:48 +0800 Message-Id: <20240801131948.10494-1-wen.yang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" The do_proc_dointvec_minmax_conv_param structure provides the minimum and maximum values for doing range checking for the proc_dointvec_minmax() handler, while the do_proc_douintvec_minmax_conv_param structure also provides these min/max values for doing range checking for the proc_douintvec_minmax()/proc_dou8vec_minmax() handlers. To avoid duplicate code, a new proc_minmax_conv_param structure has been introduced to replace both do_proc_dointvec_minmax_conv_param and do_proc_douintvec_minmax_conv_param mentioned above. This also prepares for the removal of sysctl_vals and sysctl_long_vals. Signed-off-by: Wen Yang Cc: Luis Chamberlain Cc: Kees Cook Cc: Joel Granados Cc: Eric W. Biederman Cc: Christian Brauner Cc: Dave Young Cc: linux-kernel@vger.kernel.org --- kernel/sysctl.c | 93 +++++++++++++++++++------------------------------ 1 file changed, 36 insertions(+), 57 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 79e6cb1d5c48..92305cdbb94a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -809,17 +809,18 @@ static int proc_taint(const struct ctl_table *table, = int write, } =20 /** - * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() rang= e checking structure - * @min: pointer to minimum allowable value - * @max: pointer to maximum allowable value + * struct proc_minmax_conv_param - proc_dointvec_minmax() range checking s= tructure + * @min: the minimum allowable value + * @max: the maximum allowable value * - * The do_proc_dointvec_minmax_conv_param structure provides the + * The proc_minmax_conv_param structure provides the * minimum and maximum values for doing range checking for those sysctl - * parameters that use the proc_dointvec_minmax() handler. + * parameters that use the proc_dointvec_minmax(), proc_douintvec_minmax(), + * proc_dou8vec_minmax() and so on. */ -struct do_proc_dointvec_minmax_conv_param { - int *min; - int *max; +struct proc_minmax_conv_param { + long min; + long max; }; =20 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, @@ -827,7 +828,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, uns= igned long *lvalp, int write, void *data) { int tmp, ret; - struct do_proc_dointvec_minmax_conv_param *param =3D data; + struct proc_minmax_conv_param *param =3D data; /* * If writing, first do so via a temporary local int so we can * bounds-check it before touching *valp. @@ -839,8 +840,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, uns= igned long *lvalp, return ret; =20 if (write) { - if ((param->min && *param->min > tmp) || - (param->max && *param->max < tmp)) + if ((param->min > tmp) || (param->max < tmp)) return -EINVAL; WRITE_ONCE(*valp, tmp); } @@ -867,35 +867,21 @@ static int do_proc_dointvec_minmax_conv(bool *negp, u= nsigned long *lvalp, int proc_dointvec_minmax(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct do_proc_dointvec_minmax_conv_param param =3D { - .min =3D (int *) table->extra1, - .max =3D (int *) table->extra2, - }; + struct proc_minmax_conv_param param; + + param.min =3D (table->extra1) ? *(int *) table->extra1 : INT_MIN; + param.max =3D (table->extra2) ? *(int *) table->extra2 : INT_MAX; return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_minmax_conv, ¶m); } =20 -/** - * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() ra= nge checking structure - * @min: pointer to minimum allowable value - * @max: pointer to maximum allowable value - * - * The do_proc_douintvec_minmax_conv_param structure provides the - * minimum and maximum values for doing range checking for those sysctl - * parameters that use the proc_douintvec_minmax() handler. - */ -struct do_proc_douintvec_minmax_conv_param { - unsigned int *min; - unsigned int *max; -}; - static int do_proc_douintvec_minmax_conv(unsigned long *lvalp, unsigned int *valp, int write, void *data) { int ret; unsigned int tmp; - struct do_proc_douintvec_minmax_conv_param *param =3D data; + struct proc_minmax_conv_param *param =3D data; /* write via temporary local uint for bounds-checking */ unsigned int *up =3D write ? &tmp : valp; =20 @@ -904,8 +890,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long = *lvalp, return ret; =20 if (write) { - if ((param->min && *param->min > tmp) || - (param->max && *param->max < tmp)) + if ((param->min > tmp) || (param->max < tmp)) return -ERANGE; =20 WRITE_ONCE(*valp, tmp); @@ -936,10 +921,10 @@ static int do_proc_douintvec_minmax_conv(unsigned lon= g *lvalp, int proc_douintvec_minmax(const struct ctl_table *table, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct do_proc_douintvec_minmax_conv_param param =3D { - .min =3D (unsigned int *) table->extra1, - .max =3D (unsigned int *) table->extra2, - }; + struct proc_minmax_conv_param param; + + param.min =3D (table->extra1) ? *(unsigned int *) table->extra1 : 0; + param.max =3D (table->extra2) ? *(unsigned int *) table->extra2 : UINT_MA= X; return do_proc_douintvec(table, write, buffer, lenp, ppos, do_proc_douintvec_minmax_conv, ¶m); } @@ -965,23 +950,17 @@ int proc_dou8vec_minmax(const struct ctl_table *table= , int write, void *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table tmp; - unsigned int min =3D 0, max =3D 255U, val; + unsigned int val; u8 *data =3D table->data; - struct do_proc_douintvec_minmax_conv_param param =3D { - .min =3D &min, - .max =3D &max, - }; + struct proc_minmax_conv_param param; int res; =20 /* Do not support arrays yet. */ if (table->maxlen !=3D sizeof(u8)) return -EINVAL; =20 - if (table->extra1) - min =3D *(unsigned int *) table->extra1; - if (table->extra2) - max =3D *(unsigned int *) table->extra2; - + param.min =3D (table->extra1) ? *(unsigned int *) table->extra1 : 0; + param.max =3D (table->extra2) ? *(unsigned int *) table->extra2 : 255U; tmp =3D *table; =20 tmp.maxlen =3D sizeof(val); @@ -1022,7 +1001,7 @@ static int __do_proc_doulongvec_minmax(void *data, void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul, unsigned long convdiv) { - unsigned long *i, *min, *max; + unsigned long *i, min, max; int vleft, first =3D 1, err =3D 0; size_t left; char *p; @@ -1033,8 +1012,9 @@ static int __do_proc_doulongvec_minmax(void *data, } =20 i =3D data; - min =3D table->extra1; - max =3D table->extra2; + min =3D (table->extra1) ? *(unsigned long *) table->extra1 : 0; + max =3D (table->extra2) ? *(unsigned long *) table->extra2 : ULONG_MAX; + vleft =3D table->maxlen / sizeof(unsigned long); left =3D *lenp; =20 @@ -1066,7 +1046,7 @@ static int __do_proc_doulongvec_minmax(void *data, } =20 val =3D convmul * val / convdiv; - if ((min && val < *min) || (max && val > *max)) { + if ((val < min) || (val > max)) { err =3D -EINVAL; break; } @@ -1224,7 +1204,7 @@ static int do_proc_dointvec_ms_jiffies_minmax_conv(bo= ol *negp, unsigned long *lv int *valp, int write, void *data) { int tmp, ret; - struct do_proc_dointvec_minmax_conv_param *param =3D data; + struct proc_minmax_conv_param *param =3D data; /* * If writing, first do so via a temporary local int so we can * bounds-check it before touching *valp. @@ -1236,8 +1216,7 @@ static int do_proc_dointvec_ms_jiffies_minmax_conv(bo= ol *negp, unsigned long *lv return ret; =20 if (write) { - if ((param->min && *param->min > tmp) || - (param->max && *param->max < tmp)) + if ((param->min > tmp) || (param->max < tmp)) return -EINVAL; *valp =3D tmp; } @@ -1269,10 +1248,10 @@ int proc_dointvec_jiffies(const struct ctl_table *t= able, int write, int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int wri= te, void *buffer, size_t *lenp, loff_t *ppos) { - struct do_proc_dointvec_minmax_conv_param param =3D { - .min =3D (int *) table->extra1, - .max =3D (int *) table->extra2, - }; + struct proc_minmax_conv_param param; + + param.min =3D (table->extra1) ? *(int *) table->extra1 : INT_MIN; + param.max =3D (table->extra2) ? *(int *) table->extra2 : INT_MAX; return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_ms_jiffies_minmax_conv, ¶m); } --=20 2.25.1