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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , David Ahern , Ido Schimmel , Kuniyuki Iwashima , Chia-Yu Chang , Wyatt Feng , Yung Chih Su , Hannes Frederic Sowa , Flavio Leitner , Petr Mladek , "Paul E. McKenney" , linux-kernel@vger.kernel.org References: <20261023091419.167088-1-jiayuan.chen@linux.dev> <20261023091419.167088-6-jiayuan.chen@linux.dev> Content-Language: en-US From: Fernando Fernandez Mancera In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spamd-Result: default: False [-13.50 / 50.00]; SUSE_INTERNAL_BYPASS(-9.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; XM_UA_NO_VERSION(0.01)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCPT_COUNT_TWELVE(0.00)[20]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com,icloud.com]; RCVD_TLS_ALL(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; FREEMAIL_CC(0.00)[vger.kernel.org,davemloft.net,kernel.org,redhat.com,nvidia.com,google.com,nokia-bell-labs.com,icloud.com,gmail.com,stressinduktion.org,suse.com]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; DKIM_TRACE(0.00)[suse.de:+]; DBL_BLOCKED_OPENRESOLVER(0.00)[linux.dev:email,suse.de:dkim,imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Score: -13.50 X-Spam-Level: X-Rspamd-Queue-Id: 03D8D1F74C On 10/23/26 2:19 PM, Joel Granados wrote: > On Fri, Oct 23, 2026 at 05:13:31PM +0800, Jiayuan Chen wrote: >> net.core.message_cost and net.core.message_burst feed the interval and >> burst of net_ratelimit_state, but neither has a lower bound: >> 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: ___ratelimit() treats them >> like 0, and 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 ignores >> extra1/extra2, so give message_cost a small handler that parses into a >> temporary and only stores the value if it is not negative. >> >> Fixes: a940d145cc38 ("ratelimit: Warn if ->interval or ->burst are negative") >> Cc: stable@vger.kernel.org >> Signed-off-by: Jiayuan Chen >> --- >> net/core/sysctl_net_core.c | 21 +++++++++++++++++++-- >> 1 file changed, 19 insertions(+), 2 deletions(-) >> >> diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c >> index 473c162736d6..8146ed819695 100644 >> --- a/net/core/sysctl_net_core.c >> +++ b/net/core/sysctl_net_core.c >> @@ -378,6 +378,22 @@ static int proc_do_skb_defer_max(const struct ctl_table *table, int write, >> return ret; >> } >> >> +static int proc_do_message_cost(const struct ctl_table *table, int write, >> + void *buffer, size_t *lenp, loff_t *ppos) >> +{ >> + int ret, interval = READ_ONCE(*(int *)table->data); >> + struct ctl_table tmp = *table; >> + >> + tmp.data = &interval; >> + ret = proc_dointvec_jiffies(&tmp, write, buffer, lenp, ppos); >> + if (write && !ret) { >> + if (interval < 0) >> + return -EINVAL; >> + WRITE_ONCE(*(int *)table->data, interval); >> + } >> + return ret; >> +} >> + >> #ifdef CONFIG_BPF_JIT >> static int proc_dointvec_minmax_bpf_enable(const struct ctl_table *table, int write, >> void *buffer, size_t *lenp, >> @@ -544,14 +560,15 @@ 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_do_message_cost, >> }, >> { >> .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 >> > > I would prefer something like this [1] (not tested and not compiled). > This is more in line with the patterns inside the jiffies.c file. I put > SYSCTL_ZERO there, but I have a doubt if you actually need SYSCTL_ONE. > > If the interval variable can be zero, then leave it as SYSCTL_ZERO, but > if it cant be zero and can be one the use SYSCTL_ONE > FWIW, I also like this solution and indeed we can convert other users in the future. About SYSCTL_ZERO, I believe it is the right choice. AFAIU, it just disables limiting. Thanks, Fernando. > best > > > [1] > > diff --git i/include/linux/jiffies.h w/include/linux/jiffies.h > index bbd57061802c..288ba81ed53e 100644 > --- i/include/linux/jiffies.h > +++ w/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 i/kernel/time/jiffies.c w/kernel/time/jiffies.c > index 9b3487d40cd6..cf91996fe4e3 100644 > --- i/kernel/time/jiffies.c > +++ w/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) > @@ -263,6 +271,15 @@ int proc_dointvec_jiffies(const struct ctl_table *table, int dir, > } > EXPORT_SYMBOL(proc_dointvec_jiffies); > > +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); > + > + > /** > * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds > * @table: the sysctl table > diff --git i/net/core/sysctl_net_core.c w/net/core/sysctl_net_core.c > index eb35da3556f4..7226697bf7c1 100644 > --- i/net/core/sysctl_net_core.c > +++ w/net/core/sysctl_net_core.c > @@ -538,7 +538,8 @@ 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",