| Message ID | 20211018183128.17743-1-tim.gardner@canonical.com (mailing list archive) |
|---|---|
| State | Rejected |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [linux-next] net/smc: prevent NULL dereference in smc_find_rdma_v2_device_serv() | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Single patches do not need cover letters |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | success | CCed 5 of 5 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | fail | Errors and warnings before: 4 this patch: 4 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Fixes tag looks correct |
| netdev/checkpatch | warning | WARNING: line length of 91 exceeds 80 columns |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/header_inline | success | No static functions without inline keyword in header files |
On 18/10/2021 20:31, Tim Gardner wrote: > Coverity complains of a possible NULL dereference in smc_find_rdma_v2_device_serv(). > > 1782 smc_v2_ext = smc_get_clc_v2_ext(pclc); > CID 121151 (#1 of 1): Dereference null return value (NULL_RETURNS) > 5. dereference: Dereferencing a pointer that might be NULL smc_v2_ext when calling smc_clc_match_eid. [show details] > 1783 if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL)) > 1784 goto not_found; > > Fix this by checking for NULL. Hmm that's a fundamental question for me: do we want to make the code checkers happy? While I understand that those warnings give an uneasy feeling I am not sure if the code should have additional (unneeded) checks only to avoid them. In this case all NULL checks are initially done in smc_listen_v2_check(), afterwards no more NULL checks are needed. When we would like to add them then a lot more checks are needed, e.g. 3 times in smc_find_ism_v2_device_serv() (not sure why coverity does not complain about them, too). Thoughts?
On 10/19/21 12:33 AM, Karsten Graul wrote: > On 18/10/2021 20:31, Tim Gardner wrote: >> Coverity complains of a possible NULL dereference in smc_find_rdma_v2_device_serv(). >> >> 1782 smc_v2_ext = smc_get_clc_v2_ext(pclc); >> CID 121151 (#1 of 1): Dereference null return value (NULL_RETURNS) >> 5. dereference: Dereferencing a pointer that might be NULL smc_v2_ext when calling smc_clc_match_eid. [show details] >> 1783 if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL)) >> 1784 goto not_found; >> >> Fix this by checking for NULL. > > Hmm that's a fundamental question for me: do we want to make the code checkers happy? > While I understand that those warnings give an uneasy feeling I am not sure > if the code should have additional (unneeded) checks only to avoid them. > Coverity produces a lot of false positives. I thought this one might be legitimate, but if you're comfortable that its not an issue then I'm OK with that. > In this case all NULL checks are initially done in smc_listen_v2_check(), > afterwards no more NULL checks are needed. When we would like to add them > then a lot more checks are needed, e.g. 3 times in smc_find_ism_v2_device_serv() > (not sure why coverity does not complain about them, too). > > Thoughts? > Coverity probably has produced a report from the other call sites if you've used a similar pattern, I just hadn't gotten to them yet. I'll just mark them all as false positives. rtg
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 5e50e007a7da..ff23d5b40793 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1780,7 +1780,7 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc, goto not_found; smc_v2_ext = smc_get_clc_v2_ext(pclc); - if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL)) + if (!smc_v2_ext || !smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL)) goto not_found; /* prepare RDMA check */
Coverity complains of a possible NULL dereference in smc_find_rdma_v2_device_serv(). 1782 smc_v2_ext = smc_get_clc_v2_ext(pclc); CID 121151 (#1 of 1): Dereference null return value (NULL_RETURNS) 5. dereference: Dereferencing a pointer that might be NULL smc_v2_ext when calling smc_clc_match_eid. [show details] 1783 if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL)) 1784 goto not_found; Fix this by checking for NULL. Fixes: e49300a6bf621 ("net/smc: add listen processing for SMC-Rv2") Cc: Karsten Graul <kgraul@linux.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: linux-s390@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- net/smc/af_smc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)