On Tue, Oct 27, 2026 at 06:45:33PM +0800, Jiayuan Chen wrote:
> net.core.message_cost and net.core.message_burst feed the interval and
> burst of net_ratelimit_state, but neither rejects negative values:
> message_burst uses plain proc_dointvec, and message_cost uses
> proc_dointvec_jiffies, which happily stores -1 second as -HZ jiffies.
>
> Since commit a940d145cc38 ("ratelimit: Warn if ->interval or ->burst are
> negative"), ___ratelimit() splats on such values, so the next
> net_ratelimit() caller warns, e.g. a martian source log:
>
> Negative interval (-250) or burst (10): Uninitialized ratelimit_state structure?
> WARNING: lib/ratelimit.c:43 at ___ratelimit+0x56e/0x960, CPU#1: ping/3218
> RIP: 0010:___ratelimit+0x578/0x960
> Call Trace:
>
> net_ratelimit+0x1c/0x30
> ip_handle_martian_source+0x1bb/0x340
> ip_route_input_slow+0x1057/0x3650
> ip_route_input_noref+0x104/0x260
> arp_process+0x109b/0x2510
> arp_rcv+0x381/0x460
> __netif_receive_skb_one_core+0x173/0x1c0
> __netif_receive_skb+0x21/0x150
> process_backlog+0x37e/0x1200
> __napi_poll.constprop.0+0xa5/0x5e0
> net_rx_action+0x4c0/0xf70
> handle_softirqs+0x204/0x9b0
> __do_softirq+0x10/0x18
> do_softirq.part.0+0x49/0xd0
>
>
> Negative values never meant anything here: 0 already expresses both
> "no limit" (interval) and "suppress everything" (burst).
>
> Reject them at write time. message_burst can simply use
> proc_dointvec_minmax with extra1 = 0. proc_dointvec_jiffies has no
> minmax variant, so add proc_dointvec_jiffies_minmax(), mirroring
> proc_dointvec_ms_jiffies_minmax(), and use it for message_cost with
> extra1 = 0. Note that like the ms variant, extra1/extra2 are compared
> against the converted jiffies value.
>
> Fixes: a940d145cc38 ("ratelimit: Warn if ->interval or ->burst are negative")
> Cc: stable@vger.kernel.org
> Suggested-by: Joel Granados
> Signed-off-by: Jiayuan Chen
> ---
> include/linux/jiffies.h | 2 ++
> kernel/time/jiffies.c | 40 ++++++++++++++++++++++++++++++++++++++
> net/core/sysctl_net_core.c | 6 ++++--
> 3 files changed, 46 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
> index bbd57061802cd..de12920f8e94b 100644
> --- a/include/linux/jiffies.h
> +++ b/include/linux/jiffies.h
> @@ -646,6 +646,8 @@ extern unsigned long nsecs_to_jiffies(u64 n);
> struct ctl_table;
> int proc_dointvec_jiffies(const struct ctl_table *table, int dir, void *buffer,
> size_t *lenp, loff_t *ppos);
> +int proc_dointvec_jiffies_minmax(const struct ctl_table *table, int dir,
> + void *buffer, size_t *lenp, loff_t *ppos);
> int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
> void *buffer, size_t *lenp, loff_t *ppos);
> int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int dir,
> diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
> index 9b3487d40cd6a..22a70caa58bc1 100644
> --- a/kernel/time/jiffies.c
> +++ b/kernel/time/jiffies.c
> @@ -165,6 +165,14 @@ static int do_proc_int_conv_jiffies(bool *negp, ulong *u_ptr, int *k_ptr,
> sysctl_u2k_int_conv_hz, sysctl_k2u_int_conv_hz);
> }
>
> +static int do_proc_int_conv_jiffies_minmax(bool *negp, ulong *u_ptr,
> + int *k_ptr, int dir,
> + const struct ctl_table *tbl)
> +{
> + return proc_int_conv(negp, u_ptr, k_ptr, dir, tbl, true,
> + sysctl_u2k_int_conv_hz, sysctl_k2u_int_conv_hz);
> +}
> +
> static int do_proc_int_conv_userhz_jiffies(bool *negp, ulong *u_ptr,
> int *k_ptr, int dir,
> const struct ctl_table *tbl)
> @@ -213,6 +221,13 @@ static int do_proc_int_conv_jiffies(bool *negp, ulong *u_ptr, int *k_ptr,
> return -ENOSYS;
> }
>
> +static int do_proc_int_conv_jiffies_minmax(bool *negp, ulong *u_ptr,
> + int *k_ptr, int dir,
> + const struct ctl_table *tbl)
> +{
> + return -ENOSYS;
> +}
> +
> static int do_proc_int_conv_userhz_jiffies(bool *negp, ulong *u_ptr,
> int *k_ptr, int dir,
> const struct ctl_table *tbl)
> @@ -263,6 +278,31 @@ int proc_dointvec_jiffies(const struct ctl_table *table, int dir,
> }
> EXPORT_SYMBOL(proc_dointvec_jiffies);
>
> +/**
> + * proc_dointvec_jiffies_minmax - read a vector of integers as seconds with min/max values
> + * @table: the sysctl table
> + * @dir: %TRUE if this is a write to the sysctl file
> + * @buffer: the user buffer
> + * @lenp: the size of the user buffer
> + * @ppos: file position
> + *
> + * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
> + * values from/to the user buffer, treated as an ASCII string.
> + * The values read are assumed to be in seconds, and are converted into
> + * jiffies. The converted values are checked against the optional
> + * table->extra1 (min) and table->extra2 (max) bounds, in jiffies;
> + * a value outside the range is rejected with -EINVAL.
> + *
> + * Returns 0 on success.
> + */
> +int proc_dointvec_jiffies_minmax(const struct ctl_table *table, int dir,
> + void *buffer, size_t *lenp, loff_t *ppos)
> +{
> + return proc_dointvec_conv(table, dir, buffer, lenp, ppos,
> + do_proc_int_conv_jiffies_minmax);
> +}
> +EXPORT_SYMBOL(proc_dointvec_jiffies_minmax);
> +
> /**
> * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
> * @table: the sysctl table
> diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
> index 473c162736d69..9226b96f2e89b 100644
> --- a/net/core/sysctl_net_core.c
> +++ b/net/core/sysctl_net_core.c
> @@ -544,14 +544,16 @@ static struct ctl_table net_core_table[] = {
> .data = &net_ratelimit_state.interval,
> .maxlen = sizeof(int),
> .mode = 0644,
> - .proc_handler = proc_dointvec_jiffies,
> + .proc_handler = proc_dointvec_jiffies_minmax,
> + .extra1 = SYSCTL_ZERO,
> },
> {
> .procname = "message_burst",
> .data = &net_ratelimit_state.burst,
> .maxlen = sizeof(int),
> .mode = 0644,
> - .proc_handler = proc_dointvec,
> + .proc_handler = proc_dointvec_minmax,
> + .extra1 = SYSCTL_ZERO,
> },
> #ifdef CONFIG_RPS
> {
> --
> 2.43.0
>
This LGTM
Reviewed-by: Joel Granados