diff mbox series

[net] net/smc: Avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT

Message ID 1685608912-124996-1-git-send-email-guwen@linux.alibaba.com (mailing list archive)
State Accepted
Commit c308e9ec004721a656c193243eab61a8be324657
Delegated to: Netdev Maintainers
Headers show
Series [net] net/smc: Avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT | expand

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netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers fail 1 blamed authors not CCed: ubraun@linux.ibm.com; 1 maintainers not CCed: ubraun@linux.ibm.com
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Wen Gu June 1, 2023, 8:41 a.m. UTC 
SMCRv1 has a similar issue to SMCRv2 (see link below) that may access
invalid MRs of RMBs when construct LLC ADD LINK CONT messages.

 BUG: kernel NULL pointer dereference, address: 0000000000000014
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W   E      6.4.0-rc3+ #49
 Workqueue: events smc_llc_add_link_work [smc]
 RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc]
 RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286
 RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30
 RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0
 R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000
 R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001
 FS:  0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  <TASK>
  smc_llc_srv_rkey_exchange+0xa7/0x190 [smc]
  smc_llc_srv_add_link+0x3ae/0x5a0 [smc]
  smc_llc_add_link_work+0xb8/0x140 [smc]
  process_one_work+0x1e5/0x3f0
  worker_thread+0x4d/0x2f0
  ? __pfx_worker_thread+0x10/0x10
  kthread+0xe5/0x120
  ? __pfx_kthread+0x10/0x10
  ret_from_fork+0x2c/0x50
  </TASK>

When an alernate RNIC is available in system, SMC will try to add a new
link based on the RNIC for resilience. All the RMBs in use will be mapped
to the new link. Then the RMBs' MRs corresponding to the new link will
be filled into LLC messages. For SMCRv1, they are ADD LINK CONT messages.

However smc_llc_add_link_cont() may mistakenly access to unused RMBs which
haven't been mapped to the new link and have no valid MRs, thus causing a
crash. So this patch fixes it.

Fixes: 87f88cda2128 ("net/smc: rkey processing for a new link as SMC client")
Link: https://lore.kernel.org/r/1685101741-74826-3-git-send-email-guwen@linux.alibaba.com
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 net/smc/smc_llc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Wenjia Zhang June 2, 2023, 6:22 a.m. UTC | #1 
On 01.06.23 10:41, Wen Gu wrote:
> SMCRv1 has a similar issue to SMCRv2 (see link below) that may access
> invalid MRs of RMBs when construct LLC ADD LINK CONT messages.
> 
>   BUG: kernel NULL pointer dereference, address: 0000000000000014
>   #PF: supervisor read access in kernel mode
>   #PF: error_code(0x0000) - not-present page
>   PGD 0 P4D 0
>   Oops: 0000 [#1] PREEMPT SMP PTI
>   CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W   E      6.4.0-rc3+ #49
>   Workqueue: events smc_llc_add_link_work [smc]
>   RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc]
>   RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286
>   RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000
>   RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30
>   RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0
>   R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000
>   R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001
>   FS:  0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000
>   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>   CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0
>   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>   Call Trace:
>    <TASK>
>    smc_llc_srv_rkey_exchange+0xa7/0x190 [smc]
>    smc_llc_srv_add_link+0x3ae/0x5a0 [smc]
>    smc_llc_add_link_work+0xb8/0x140 [smc]
>    process_one_work+0x1e5/0x3f0
>    worker_thread+0x4d/0x2f0
>    ? __pfx_worker_thread+0x10/0x10
>    kthread+0xe5/0x120
>    ? __pfx_kthread+0x10/0x10
>    ret_from_fork+0x2c/0x50
>    </TASK>
> 
> When an alernate RNIC is available in system, SMC will try to add a new
> link based on the RNIC for resilience. All the RMBs in use will be mapped
> to the new link. Then the RMBs' MRs corresponding to the new link will
> be filled into LLC messages. For SMCRv1, they are ADD LINK CONT messages.
> 
> However smc_llc_add_link_cont() may mistakenly access to unused RMBs which
> haven't been mapped to the new link and have no valid MRs, thus causing a
> crash. So this patch fixes it.
> 
> Fixes: 87f88cda2128 ("net/smc: rkey processing for a new link as SMC client")
> Link: https://lore.kernel.org/r/1685101741-74826-3-git-send-email-guwen@linux.alibaba.com
> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
> ---
>   net/smc/smc_llc.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
> index 7a8d916..90f0b60 100644
> --- a/net/smc/smc_llc.c
> +++ b/net/smc/smc_llc.c
> @@ -851,6 +851,8 @@ static int smc_llc_add_link_cont(struct smc_link *link,
>   	addc_llc->num_rkeys = *num_rkeys_todo;
>   	n = *num_rkeys_todo;
>   	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
> +		while (*buf_pos && !(*buf_pos)->used)
> +			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
>   		if (!*buf_pos) {
>   			addc_llc->num_rkeys = addc_llc->num_rkeys -
>   					      *num_rkeys_todo;
> @@ -867,8 +869,6 @@ static int smc_llc_add_link_cont(struct smc_link *link,
>   
>   		(*num_rkeys_todo)--;
>   		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
> -		while (*buf_pos && !(*buf_pos)->used)
> -			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
>   	}
>   	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
>   	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);

looks good to me! Thank you for fixing that!

Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Tony Lu June 2, 2023, 7:42 a.m. UTC | #2 
On Thu, Jun 01, 2023 at 04:41:52PM +0800, Wen Gu wrote:
> SMCRv1 has a similar issue to SMCRv2 (see link below) that may access
> invalid MRs of RMBs when construct LLC ADD LINK CONT messages.
> 
>  BUG: kernel NULL pointer dereference, address: 0000000000000014
>  #PF: supervisor read access in kernel mode
>  #PF: error_code(0x0000) - not-present page
>  PGD 0 P4D 0
>  Oops: 0000 [#1] PREEMPT SMP PTI
>  CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W   E      6.4.0-rc3+ #49
>  Workqueue: events smc_llc_add_link_work [smc]
>  RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc]
>  RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286
>  RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000
>  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30
>  RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0
>  R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000
>  R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001
>  FS:  0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0
>  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>  Call Trace:
>   <TASK>
>   smc_llc_srv_rkey_exchange+0xa7/0x190 [smc]
>   smc_llc_srv_add_link+0x3ae/0x5a0 [smc]
>   smc_llc_add_link_work+0xb8/0x140 [smc]
>   process_one_work+0x1e5/0x3f0
>   worker_thread+0x4d/0x2f0
>   ? __pfx_worker_thread+0x10/0x10
>   kthread+0xe5/0x120
>   ? __pfx_kthread+0x10/0x10
>   ret_from_fork+0x2c/0x50
>   </TASK>
> 
> When an alernate RNIC is available in system, SMC will try to add a new
> link based on the RNIC for resilience. All the RMBs in use will be mapped
> to the new link. Then the RMBs' MRs corresponding to the new link will
> be filled into LLC messages. For SMCRv1, they are ADD LINK CONT messages.
> 
> However smc_llc_add_link_cont() may mistakenly access to unused RMBs which
> haven't been mapped to the new link and have no valid MRs, thus causing a
> crash. So this patch fixes it.
> 
> Fixes: 87f88cda2128 ("net/smc: rkey processing for a new link as SMC client")
> Link: https://lore.kernel.org/r/1685101741-74826-3-git-send-email-guwen@linux.alibaba.com
> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>

This SGTM, thanks.

Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

> ---
>  net/smc/smc_llc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
> index 7a8d916..90f0b60 100644
> --- a/net/smc/smc_llc.c
> +++ b/net/smc/smc_llc.c
> @@ -851,6 +851,8 @@ static int smc_llc_add_link_cont(struct smc_link *link,
>  	addc_llc->num_rkeys = *num_rkeys_todo;
>  	n = *num_rkeys_todo;
>  	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
> +		while (*buf_pos && !(*buf_pos)->used)
> +			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
>  		if (!*buf_pos) {
>  			addc_llc->num_rkeys = addc_llc->num_rkeys -
>  					      *num_rkeys_todo;
> @@ -867,8 +869,6 @@ static int smc_llc_add_link_cont(struct smc_link *link,
>  
>  		(*num_rkeys_todo)--;
>  		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
> -		while (*buf_pos && !(*buf_pos)->used)
> -			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
>  	}
>  	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
>  	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);
> -- 
> 1.8.3.1
patchwork-bot+netdevbpf@kernel.org June 3, 2023, 8:02 p.m. UTC | #3 
Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Thu,  1 Jun 2023 16:41:52 +0800 you wrote:
> SMCRv1 has a similar issue to SMCRv2 (see link below) that may access
> invalid MRs of RMBs when construct LLC ADD LINK CONT messages.
> 
>  BUG: kernel NULL pointer dereference, address: 0000000000000014
>  #PF: supervisor read access in kernel mode
>  #PF: error_code(0x0000) - not-present page
>  PGD 0 P4D 0
>  Oops: 0000 [#1] PREEMPT SMP PTI
>  CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W   E      6.4.0-rc3+ #49
>  Workqueue: events smc_llc_add_link_work [smc]
>  RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc]
>  RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286
>  RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000
>  RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30
>  RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0
>  R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000
>  R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001
>  FS:  0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0
>  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>  Call Trace:
>   <TASK>
>   smc_llc_srv_rkey_exchange+0xa7/0x190 [smc]
>   smc_llc_srv_add_link+0x3ae/0x5a0 [smc]
>   smc_llc_add_link_work+0xb8/0x140 [smc]
>   process_one_work+0x1e5/0x3f0
>   worker_thread+0x4d/0x2f0
>   ? __pfx_worker_thread+0x10/0x10
>   kthread+0xe5/0x120
>   ? __pfx_kthread+0x10/0x10
>   ret_from_fork+0x2c/0x50
>   </TASK>
> 
> [...]

Here is the summary with links:
  - [net] net/smc: Avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONT
    https://git.kernel.org/netdev/net/c/c308e9ec0047

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 7a8d916..90f0b60 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -851,6 +851,8 @@  static int smc_llc_add_link_cont(struct smc_link *link,
 	addc_llc->num_rkeys = *num_rkeys_todo;
 	n = *num_rkeys_todo;
 	for (i = 0; i < min_t(u8, n, SMC_LLC_RKEYS_PER_CONT_MSG); i++) {
+		while (*buf_pos && !(*buf_pos)->used)
+			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 		if (!*buf_pos) {
 			addc_llc->num_rkeys = addc_llc->num_rkeys -
 					      *num_rkeys_todo;
@@ -867,8 +869,6 @@  static int smc_llc_add_link_cont(struct smc_link *link,
 
 		(*num_rkeys_todo)--;
 		*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
-		while (*buf_pos && !(*buf_pos)->used)
-			*buf_pos = smc_llc_get_next_rmb(lgr, buf_lst, *buf_pos);
 	}
 	addc_llc->hd.common.llc_type = SMC_LLC_ADD_LINK_CONT;
 	addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont);