sysctl: Two jiffies converter regressions from 2dc164a48e6f - #2661
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proc_int_k2u_conv_kop() reports the sign through *negp and the magnitude through *u_ptr, but for a negative value it hands the sign-extended int to the converter and negates the result: *u_ptr = k_ptr_op ? -k_ptr_op((ulong)val) : -(ulong)val; With div_hz() and HZ=1000 a stored -1000 becomes (ulong)-1000 / 1000 == 18446744073709550, and negating that wraps: # echo -1 > /proc/sys/net/ipv4/tcp_fin_timeout # cat /proc/sys/net/ipv4/tcp_fin_timeout -18428297329635842066 Take the magnitude first and convert that, which is what the open-coded version did before commit 2dc164a ("sysctl: Create converter functions with two new macros") folded it into a macro. The k_ptr_op == NULL branch was already correct. proc_dointvec_jiffies() and proc_dointvec_ms_jiffies() are affected. Fixes: 2dc164a ("sysctl: Create converter functions with two new macros") Cc: stable@vger.kernel.org Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
mult_hz() converts a user-supplied seconds value to jiffies for proc_dointvec_jiffies(). proc_int_u2k_conv_uop() rejects a result above INT_MAX, but it inspects the product, so a product that wraps arrives as a small value and is stored: # echo 18446744073709552 > /proc/sys/net/ipv4/tcp_keepalive_time # cat /proc/sys/net/ipv4/tcp_keepalive_time 0 One less is rejected; that value wraps to 384 jiffies at HZ=1000. 65 sysctls use proc_dointvec_jiffies(), among them tcp_keepalive_time, tcp_fin_timeout and the conntrack timeouts. Bound the input in the shape clock_t_to_jiffies() already uses and leave the INT_MAX policy to the caller. The bound was open-coded as "*lvalp > INT_MAX / HZ" until commit 2dc164a ("sysctl: Create converter functions with two new macros"). Fixes: 2dc164a ("sysctl: Create converter functions with two new macros") Cc: stable@vger.kernel.org Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
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Superseded by series 1174867 (v2). Closing automatically. Automated by ml2pr |
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Series: https://patchwork.kernel.org/project/linux-fsdevel/list/?series=1170939
Submitter: Zhan Xusheng
Version: 1
Patches: 2/2
Message-ID:
<20260922031229.2300283-1-zhanxusheng@xiaomi.com>Base: vfs.base.ci
Lore: https://lore.kernel.org/linux-fsdevel/20260922031229.2300283-1-zhanxusheng@xiaomi.com
Automated by ml2pr