the returned buffer of register_sysctl() is stored into net_header variable, but net_header is not used after, and compiler maybe optimise the variable out, and lead kmemleak reported the below warning comm "swapper/0", pid 1, jiffies 4294937448 (age 267.270s) hex dump (first 32 bytes): 90 38 8b 01 c0 ff ff ff 00 00 00 00 01 00 00 00 .8.............. 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffc00020f134>] create_object+0x10c/0x2a0 [<ffffffc00070ff44>] kmemleak_alloc+0x54/0xa0 [<ffffffc0001fe378>] __kmalloc+0x1f8/0x4f8 [<ffffffc00028e984>] __register_sysctl_table+0x64/0x5a0 [<ffffffc00028eef0>] register_sysctl+0x30/0x40 [<ffffffc00099c304>] net_sysctl_init+0x20/0x58 [<ffffffc000994dd8>] sock_init+0x10/0xb0 [<ffffffc0000842e0>] do_one_initcall+0x90/0x1b8 [<ffffffc000966bac>] kernel_init_freeable+0x218/0x2f0 [<ffffffc00070ed6c>] kernel_init+0x1c/0xe8 [<ffffffc000083bfc>] ret_from_fork+0xc/0x50 [<ffffffffffffffff>] 0xffffffffffffffff <<end check kmemleak>> Before fix, the objdump result on ARM64: 0000000000000000 <net_sysctl_init>: 0: a9be7bfd stp x29, x30, [sp,#-32]! 4: 90000001 adrp x1, 0 <net_sysctl_init> 8: 90000000 adrp x0, 0 <net_sysctl_init> c: 910003fd mov x29, sp 10: 91000021 add x1, x1, #0x0 14: 91000000 add x0, x0, #0x0 18: a90153f3 stp x19, x20, [sp,#16] 1c: 12800174 mov w20, #0xfffffff4 // #-12 20: 94000000 bl 0 <register_sysctl> 24: b4000120 cbz x0, 48 <net_sysctl_init+0x48> 28: 90000013 adrp x19, 0 <net_sysctl_init> 2c: 91000273 add x19, x19, #0x0 30: 9101a260 add x0, x19, #0x68 34: 94000000 bl 0 <register_pernet_subsys> 38: 2a0003f4 mov w20, w0 3c: 35000060 cbnz w0, 48 <net_sysctl_init+0x48> 40: aa1303e0 mov x0, x19 44: 94000000 bl 0 <register_sysctl_root> 48: 2a1403e0 mov w0, w20 4c: a94153f3 ldp x19, x20, [sp,#16] 50: a8c27bfd ldp x29, x30, [sp],#32 54: d65f03c0 ret After: 0000000000000000 <net_sysctl_init>: 0: a9bd7bfd stp x29, x30, [sp,#-48]! 4: 90000000 adrp x0, 0 <net_sysctl_init> 8: 910003fd mov x29, sp c: a90153f3 stp x19, x20, [sp,#16] 10: 90000013 adrp x19, 0 <net_sysctl_init> 14: 91000000 add x0, x0, #0x0 18: 91000273 add x19, x19, #0x0 1c: f90013f5 str x21, [sp,#32] 20: aa1303e1 mov x1, x19 24: 12800175 mov w21, #0xfffffff4 // #-12 28: 94000000 bl 0 <register_sysctl> 2c: f9002260 str x0, [x19,#64] 30: b40001a0 cbz x0, 64 <net_sysctl_init+0x64> 34: 90000014 adrp x20, 0 <net_sysctl_init> 38: 91000294 add x20, x20, #0x0 3c: 9101a280 add x0, x20, #0x68 40: 94000000 bl 0 <register_pernet_subsys> 44: 2a0003f5 mov w21, w0 48: 35000080 cbnz w0, 58 <net_sysctl_init+0x58> 4c: aa1403e0 mov x0, x20 50: 94000000 bl 0 <register_sysctl_root> 54: 14000004 b 64 <net_sysctl_init+0x64> 58: f9402260 ldr x0, [x19,#64] 5c: 94000000 bl 0 <unregister_sysctl_table> 60: f900227f str xzr, [x19,#64] 64: 2a1503e0 mov w0, w21 68: f94013f5 ldr x21, [sp,#32] 6c: a94153f3 ldp x19, x20, [sp,#16] 70: a8c37bfd ldp x29, x30, [sp],#48 74: d65f03c0 ret Add the possible error handle to free the net_header to remove the kmemleak warning Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Modify the code to use current_euid(), and in_egroup_p, as in done in fs/proc/proc_sysctl.c:test_perm() Cc: stable@vger.kernel.org Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reported-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get rid of duplicate code in net_ctl_permissions and fix the comment. Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
- Allow anyone with CAP_NET_ADMIN rights in the user namespace of the the netowrk namespace to change sysctls. - Allow anyone the uid of the user namespace root the same permissions over the network namespace sysctls as the global root. - Allow anyone with gid of the user namespace root group the same permissions over the network namespace sysctl as the global root group. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
- Current is implicitly avaiable so passing current->nsproxy isn't useful. - The ctl_table_header is needed to find how the sysctl table is connected to the rest of sysctl. - ctl_table_root is avaiable in the ctl_table_header so no need to it. With these changes it becomes possible to write a version of net_sysctl_permission that takes into account the network namespace of the sysctl table, an important feature in extending the user namespace. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
We are going to delete the Token ring support. This removes any special processing in the core networking for token ring, (aside from net/tr.c itself), leaving the drivers and remaining tokenring support present but inert. The mass removal of the drivers and net/tr.c will be in a separate commit, so that the history of these files that we still care about won't have the giant deletion tied into their history. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
All of the users have been converted to use registera_net_sysctl so we no longer need register_net_sysctl. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
register_sysctl_rotable never caught on as an interesting way to register sysctls. My take on the situation is that what we want are sysctls that we can only see in the initial network namespace. What we have implemented with register_sysctl_rotable are sysctls that we can see in all of the network namespaces and can only change in the initial network namespace. That is a very silly way to go. Just register the network sysctls in the initial network namespace and we don't have any weird special cases to deal with. The sysctls affected are: /proc/sys/net/ipv4/ipfrag_secret_interval /proc/sys/net/ipv4/ipfrag_max_dist /proc/sys/net/ipv6/ip6frag_secret_interval /proc/sys/net/ipv6/mld_max_msf I really don't expect anyone will miss them if they can't read them in a child user namespace. CC: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
If the netfilter code is modified to use register_net_sysctl_table the kernel fails to boot because the per net sysctl infrasturce is not setup soon enough. So to avoid races call net_sysctl_init from sock_init(). Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Implementation limitations of the sysctl core won't let /proc/sys/net reside in a network namespace. /proc/sys/net at least must be registered as a normal sysctl. So register /proc/sys/net early as an empty directory to guarantee we don't violate this constraint and hit bugs in the sysctl implementation. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>