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sysctl: fix write access to dmesg_restrict/kptr_restrict

Commit bfdc0b4 adds code to restrict access to dmesg_restrict, however, it incorrectly alters kptr_restrict rather than dmesg_restrict. The original patch from Richard Weinberger (https://lkml.org/lkml/2011/3/14/362) alters dmesg_restrict as expected, and so the patch seems to have been misapplied. This adds the CAP_SYS_ADMIN check to both dmesg_restrict and kptr_restrict, since both are sensitive.

Kees Cook committed 14 years ago

Commit 620f6e81 parent 6c216ec1 file · +4 −4Browse files

Unified · Split

kernel/sysctl.c+4−4
@@ -170,7 +170,7 @@ static int proc_taint(struct ctl_table *table, int write, · 169 unmodified lines
170#endif170#endif
171 171
172#ifdef CONFIG_PRINTK172#ifdef CONFIG_PRINTK
173static int proc_dmesg_restrict(struct ctl_table *table, int write,173static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
174 void __user *buffer, size_t *lenp, loff_t *ppos);174 void __user *buffer, size_t *lenp, loff_t *ppos);
175#endif175#endif
176 176
@@ -703,7 +703,7 @@ static struct ctl_table kern_table[] = { · 526 unmodified lines
703 .data = &dmesg_restrict,703 .data = &dmesg_restrict,
704 .maxlen = sizeof(int),704 .maxlen = sizeof(int),
705 .mode = 0644,705 .mode = 0644,
706 .proc_handler = proc_dointvec_minmax,706 .proc_handler = proc_dointvec_minmax_sysadmin,
707 .extra1 = &zero,707 .extra1 = &zero,
708 .extra2 = &one,708 .extra2 = &one,
709 },709 },
@@ -712,7 +712,7 @@ static struct ctl_table kern_table[] = { · 2 unmodified lines
712 .data = &kptr_restrict,712 .data = &kptr_restrict,
713 .maxlen = sizeof(int),713 .maxlen = sizeof(int),
714 .mode = 0644,714 .mode = 0644,
715 .proc_handler = proc_dmesg_restrict,715 .proc_handler = proc_dointvec_minmax_sysadmin,
716 .extra1 = &zero,716 .extra1 = &zero,
717 .extra2 = &two,717 .extra2 = &two,
718 },718 },
@@ -1943,7 +1943,7 @@ static int proc_taint(struct ctl_table *table, int write, · 1224 unmodified lines
1943}1943}
1944 1944
1945#ifdef CONFIG_PRINTK1945#ifdef CONFIG_PRINTK
1946static int proc_dmesg_restrict(struct ctl_table *table, int write,1946static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
1947 void __user *buffer, size_t *lenp, loff_t *ppos)1947 void __user *buffer, size_t *lenp, loff_t *ppos)
1948{1948{
1949 if (write && !capable(CAP_SYS_ADMIN))1949 if (write && !capable(CAP_SYS_ADMIN))