From cffda199e1decf3e3b80f757bcec27faad09e9d7 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 5 Dec 2022 12:09:06 -0800 Subject: [PATCH] UPSTREAM: proc: proc_skip_spaces() shouldn't think it is working on C strings commit bce9332220bd677d83b19d21502776ad555a0e73 upstream. proc_skip_spaces() seems to think it is working on C strings, and ends up being just a wrapper around skip_spaces() with a really odd calling convention. Instead of basing it on skip_spaces(), it should have looked more like proc_skip_char(), which really is the exact same function (except it skips a particular character, rather than whitespace). So use that as inspiration, odd coding and all. Now the calling convention actually makes sense and works for the intended purpose. Bug: 261488859 Reported-and-tested-by: Kyle Zeng Acked-by: Eric Dumazet Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Lee Jones Change-Id: Ie21bf20f3b92b78c5f31093b354a77b4133810e7 Signed-off-by: Lee Jones --- kernel/sysctl.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 96b8c50d1b1a..0c8720e07aa5 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2165,13 +2165,14 @@ int proc_dostring(struct ctl_table *table, int write, (char __user *)buffer, lenp, ppos); } -static size_t proc_skip_spaces(char **buf) +static void proc_skip_spaces(char **buf, size_t *size) { - size_t ret; - char *tmp = skip_spaces(*buf); - ret = tmp - *buf; - *buf = tmp; - return ret; + while (*size) { + if (!isspace(**buf)) + break; + (*size)--; + (*buf)++; + } } static void proc_skip_char(char **buf, size_t *size, const char v) @@ -2409,7 +2410,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, bool neg; if (write) { - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); if (!left) break; @@ -2440,7 +2441,7 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, if (!write && !first && left && !err) err = proc_put_char(&buffer, &left, '\n'); if (write && !err && left) - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); if (write) { kfree(kbuf); if (first) @@ -2489,7 +2490,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data, if (IS_ERR(kbuf)) return -EINVAL; - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); if (!left) { err = -EINVAL; goto out_free; @@ -2509,7 +2510,7 @@ static int do_proc_douintvec_w(unsigned int *tbl_data, } if (!err && left) - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); out_free: kfree(kbuf); @@ -2923,7 +2924,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int if (write) { bool neg; - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); if (!left) break; @@ -2956,7 +2957,7 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int if (!write && !first && left && !err) err = proc_put_char(&buffer, &left, '\n'); if (write && !err) - left -= proc_skip_spaces(&p); + proc_skip_spaces(&p, &left); if (write) { kfree(kbuf); if (first)