| Message ID | 20250107-mptcp-sysfs-netns-v1-5-2fa7075d9970@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | a18c9552dca0c6ca1e241f736e45bbf57589dba7 |
| Delegated to: | Matthieu Baerts |
| Headers | show |
| Series | net: sysctl: avoid using current->nsproxy | expand |
| Context | Check | Description |
|---|---|---|
| matttbe/build | success | Build and static analysis OK |
| matttbe/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 16 lines checked |
| matttbe/shellcheck | success | MPTCP selftests files have not been modified |
| matttbe/KVM_Validation__normal | success | Success! ✅ |
| matttbe/KVM_Validation__debug | success | Success! ✅ |
| matttbe/KVM_Validation__btf-normal__only_bpftest_all_ | success | Success! ✅ |
| matttbe/KVM_Validation__btf-debug__only_bpftest_all_ | success | Success! ✅ |
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 9848d19630a4f760238a3a2abd3ec823f012d34a..a5285815264dfa9d88d1d71244f309448e97a506 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c @@ -433,7 +433,7 @@ static int proc_sctp_do_hmac_alg(const struct ctl_table *ctl, int write, static int proc_sctp_do_rto_min(const struct ctl_table *ctl, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct net *net = current->nsproxy->net_ns; + struct net *net = container_of(ctl->data, struct net, sctp.rto_min); unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; struct ctl_table tbl; @@ -461,7 +461,7 @@ static int proc_sctp_do_rto_min(const struct ctl_table *ctl, int write, static int proc_sctp_do_rto_max(const struct ctl_table *ctl, int write, void *buffer, size_t *lenp, loff_t *ppos) { - struct net *net = current->nsproxy->net_ns; + struct net *net = container_of(ctl->data, struct net, sctp.rto_max); unsigned int min = *(unsigned int *) ctl->extra1; unsigned int max = *(unsigned int *) ctl->extra2; struct ctl_table tbl;
As mentioned in a previous commit of this series, using the 'net' structure via 'current' is not recommended for different reasons: - Inconsistency: getting info from the reader's/writer's netns vs only from the opener's netns. - current->nsproxy can be NULL in some cases, resulting in an 'Oops' (null-ptr-deref), e.g. when the current task is exiting, as spotted by syzbot [1] using acct(2). The 'net' structure can be obtained from the table->data using container_of(). Note that table->data could also be used directly, as this is the only member needed from the 'net' structure, but that would increase the size of this fix, to use '*data' everywhere 'net->sctp.rto_min/max' is used. Fixes: 4f3fdf3bc59c ("sctp: add check rto_min and rto_max in sysctl") Link: https://lore.kernel.org/67769ecb.050a0220.3a8527.003f.GAE@google.com [1] Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- net/sctp/sysctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)