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* FAILED: patch "[PATCH] writeback: fix dereferencing NULL mapping->host on" failed to apply to 5.4-stable tree
@ 2023-06-23  9:23 gregkh
  2023-06-23 13:46 ` [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template Rafael Aquini
  0 siblings, 1 reply; 4+ messages in thread
From: gregkh @ 2023-06-23  9:23 UTC (permalink / raw)
  To: aquini, akpm, aris, laoar.shao, stable; +Cc: stable


The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 54abe19e00cfcc5a72773d15cd00ed19ab763439
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023062336-squall-impotence-3b78@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 54abe19e00cfcc5a72773d15cd00ed19ab763439 Mon Sep 17 00:00:00 2001
From: Rafael Aquini <aquini@redhat.com>
Date: Tue, 6 Jun 2023 19:36:13 -0400
Subject: [PATCH] writeback: fix dereferencing NULL mapping->host on
 writeback_page_template

When commit 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for
wait_on_page_writeback()") repurposed the writeback_dirty_page trace event
as a template to create its new wait_on_page_writeback trace event, it
ended up opening a window to NULL pointer dereference crashes due to the
(infrequent) occurrence of a race where an access to a page in the
swap-cache happens concurrently with the moment this page is being written
to disk and the tracepoint is enabled:

    BUG: kernel NULL pointer dereference, address: 0000000000000040
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 800000010ec0a067 P4D 800000010ec0a067 PUD 102353067 PMD 0
    Oops: 0000 [#1] PREEMPT SMP PTI
    CPU: 1 PID: 1320 Comm: shmem-worker Kdump: loaded Not tainted 6.4.0-rc5+ #13
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230301gitf80f052277c8-1.fc37 03/01/2023
    RIP: 0010:trace_event_raw_event_writeback_folio_template+0x76/0xf0
    Code: 4d 85 e4 74 5c 49 8b 3c 24 e8 06 98 ee ff 48 89 c7 e8 9e 8b ee ff ba 20 00 00 00 48 89 ef 48 89 c6 e8 fe d4 1a 00 49 8b 04 24 <48> 8b 40 40 48 89 43 28 49 8b 45 20 48 89 e7 48 89 43 30 e8 a2 4d
    RSP: 0000:ffffaad580b6fb60 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: ffff90e38035c01c RCX: 0000000000000000
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e38035c044
    RBP: ffff90e38035c024 R08: 0000000000000002 R09: 0000000000000006
    R10: ffff90e38035c02e R11: 0000000000000020 R12: ffff90e380bac000
    R13: ffffe3a7456d9200 R14: 0000000000001b81 R15: ffffe3a7456d9200
    FS:  00007f2e4e8a15c0(0000) GS:ffff90e3fbc80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000040 CR3: 00000001150c6003 CR4: 0000000000170ee0
    Call Trace:
     <TASK>
     ? __die+0x20/0x70
     ? page_fault_oops+0x76/0x170
     ? kernelmode_fixup_or_oops+0x84/0x110
     ? exc_page_fault+0x65/0x150
     ? asm_exc_page_fault+0x22/0x30
     ? trace_event_raw_event_writeback_folio_template+0x76/0xf0
     folio_wait_writeback+0x6b/0x80
     shmem_swapin_folio+0x24a/0x500
     ? filemap_get_entry+0xe3/0x140
     shmem_get_folio_gfp+0x36e/0x7c0
     ? find_busiest_group+0x43/0x1a0
     shmem_fault+0x76/0x2a0
     ? __update_load_avg_cfs_rq+0x281/0x2f0
     __do_fault+0x33/0x130
     do_read_fault+0x118/0x160
     do_pte_missing+0x1ed/0x2a0
     __handle_mm_fault+0x566/0x630
     handle_mm_fault+0x91/0x210
     do_user_addr_fault+0x22c/0x740
     exc_page_fault+0x65/0x150
     asm_exc_page_fault+0x22/0x30

This problem arises from the fact that the repurposed writeback_dirty_page
trace event code was written assuming that every pointer to mapping
(struct address_space) would come from a file-mapped page-cache object,
thus mapping->host would always be populated, and that was a valid case
before commit 19343b5bdd16.  The swap-cache address space
(swapper_spaces), however, doesn't populate its ->host (struct inode)
pointer, thus leading to the crashes in the corner-case aforementioned.

commit 19343b5bdd16 ended up breaking the assignment of __entry->name and
__entry->ino for the wait_on_page_writeback tracepoint -- both dependent
on mapping->host carrying a pointer to a valid inode.  The assignment of
__entry->name was fixed by commit 68f23b89067f ("memcg: fix a crash in
wb_workfn when a device disappears"), and this commit fixes the remaining
case, for __entry->ino.

Link: https://lkml.kernel.org/r/20230606233613.1290819-1-aquini@redhat.com
Fixes: 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for wait_on_page_writeback()")
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 86b2a82da546..54e353c9f919 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -68,7 +68,7 @@ DECLARE_EVENT_CLASS(writeback_folio_template,
 		strscpy_pad(__entry->name,
 			    bdi_dev_name(mapping ? inode_to_bdi(mapping->host) :
 					 NULL), 32);
-		__entry->ino = mapping ? mapping->host->i_ino : 0;
+		__entry->ino = (mapping && mapping->host) ? mapping->host->i_ino : 0;
 		__entry->index = folio->index;
 	),
 


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template
  2023-06-23  9:23 FAILED: patch "[PATCH] writeback: fix dereferencing NULL mapping->host on" failed to apply to 5.4-stable tree gregkh
@ 2023-06-23 13:46 ` Rafael Aquini
  2023-06-24 14:04   ` Greg KH
  0 siblings, 1 reply; 4+ messages in thread
From: Rafael Aquini @ 2023-06-23 13:46 UTC (permalink / raw)
  To: stable; +Cc: Yafang Shao, Aristeu Rozanski, Andrew Morton

commit 54abe19e00cfcc5a72773d15cd00ed19ab763439 upstream.

When commit 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for
wait_on_page_writeback()") repurposed the writeback_dirty_page trace event
as a template to create its new wait_on_page_writeback trace event, it
ended up opening a window to NULL pointer dereference crashes due to the
(infrequent) occurrence of a race where an access to a page in the
swap-cache happens concurrently with the moment this page is being written
to disk and the tracepoint is enabled:

    BUG: kernel NULL pointer dereference, address: 0000000000000040
    #PF: supervisor read access in kernel mode
    #PF: error_code(0x0000) - not-present page
    PGD 800000010ec0a067 P4D 800000010ec0a067 PUD 102353067 PMD 0
    Oops: 0000 [#1] PREEMPT SMP PTI
    CPU: 1 PID: 1320 Comm: shmem-worker Kdump: loaded Not tainted 6.4.0-rc5+ #13
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230301gitf80f052277c8-1.fc37 03/01/2023
    RIP: 0010:trace_event_raw_event_writeback_folio_template+0x76/0xf0
    Code: 4d 85 e4 74 5c 49 8b 3c 24 e8 06 98 ee ff 48 89 c7 e8 9e 8b ee ff ba 20 00 00 00 48 89 ef 48 89 c6 e8 fe d4 1a 00 49 8b 04 24 <48> 8b 40 40 48 89 43 28 49 8b 45 20 48 89 e7 48 89 43 30 e8 a2 4d
    RSP: 0000:ffffaad580b6fb60 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: ffff90e38035c01c RCX: 0000000000000000
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e38035c044
    RBP: ffff90e38035c024 R08: 0000000000000002 R09: 0000000000000006
    R10: ffff90e38035c02e R11: 0000000000000020 R12: ffff90e380bac000
    R13: ffffe3a7456d9200 R14: 0000000000001b81 R15: ffffe3a7456d9200
    FS:  00007f2e4e8a15c0(0000) GS:ffff90e3fbc80000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000040 CR3: 00000001150c6003 CR4: 0000000000170ee0
    Call Trace:
     <TASK>
     ? __die+0x20/0x70
     ? page_fault_oops+0x76/0x170
     ? kernelmode_fixup_or_oops+0x84/0x110
     ? exc_page_fault+0x65/0x150
     ? asm_exc_page_fault+0x22/0x30
     ? trace_event_raw_event_writeback_folio_template+0x76/0xf0
     folio_wait_writeback+0x6b/0x80
     shmem_swapin_folio+0x24a/0x500
     ? filemap_get_entry+0xe3/0x140
     shmem_get_folio_gfp+0x36e/0x7c0
     ? find_busiest_group+0x43/0x1a0
     shmem_fault+0x76/0x2a0
     ? __update_load_avg_cfs_rq+0x281/0x2f0
     __do_fault+0x33/0x130
     do_read_fault+0x118/0x160
     do_pte_missing+0x1ed/0x2a0
     __handle_mm_fault+0x566/0x630
     handle_mm_fault+0x91/0x210
     do_user_addr_fault+0x22c/0x740
     exc_page_fault+0x65/0x150
     asm_exc_page_fault+0x22/0x30

This problem arises from the fact that the repurposed writeback_dirty_page
trace event code was written assuming that every pointer to mapping
(struct address_space) would come from a file-mapped page-cache object,
thus mapping->host would always be populated, and that was a valid case
before commit 19343b5bdd16.  The swap-cache address space
(swapper_spaces), however, doesn't populate its ->host (struct inode)
pointer, thus leading to the crashes in the corner-case aforementioned.

commit 19343b5bdd16 ended up breaking the assignment of __entry->name and
__entry->ino for the wait_on_page_writeback tracepoint -- both dependent
on mapping->host carrying a pointer to a valid inode.  The assignment of
__entry->name was fixed by commit 68f23b89067f ("memcg: fix a crash in
wb_workfn when a device disappears"), and this commit fixes the remaining
case, for __entry->ino.

Link: https://lkml.kernel.org/r/20230606233613.1290819-1-aquini@redhat.com
Fixes: 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for wait_on_page_writeback()")
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Aristeu Rozanski <aris@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael Aquini <aquini@redhat.com>
---
 include/trace/events/writeback.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index 011e8faa608b..b70c32e4a491 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -68,7 +68,7 @@ DECLARE_EVENT_CLASS(writeback_page_template,
 		strscpy_pad(__entry->name,
 			    bdi_dev_name(mapping ? inode_to_bdi(mapping->host) :
 					 NULL), 32);
-		__entry->ino = mapping ? mapping->host->i_ino : 0;
+		__entry->ino = (mapping && mapping->host) ? mapping->host->i_ino : 0;
 		__entry->index = page->index;
 	),
 
-- 
2.39.2


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template
  2023-06-23 13:46 ` [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template Rafael Aquini
@ 2023-06-24 14:04   ` Greg KH
  2023-06-24 20:26     ` Rafael Aquini
  0 siblings, 1 reply; 4+ messages in thread
From: Greg KH @ 2023-06-24 14:04 UTC (permalink / raw)
  To: Rafael Aquini; +Cc: stable, Yafang Shao, Aristeu Rozanski, Andrew Morton

On Fri, Jun 23, 2023 at 09:46:01AM -0400, Rafael Aquini wrote:
> commit 54abe19e00cfcc5a72773d15cd00ed19ab763439 upstream.
> 
> When commit 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for
> wait_on_page_writeback()") repurposed the writeback_dirty_page trace event
> as a template to create its new wait_on_page_writeback trace event, it
> ended up opening a window to NULL pointer dereference crashes due to the
> (infrequent) occurrence of a race where an access to a page in the
> swap-cache happens concurrently with the moment this page is being written
> to disk and the tracepoint is enabled:
> 
>     BUG: kernel NULL pointer dereference, address: 0000000000000040
>     #PF: supervisor read access in kernel mode
>     #PF: error_code(0x0000) - not-present page
>     PGD 800000010ec0a067 P4D 800000010ec0a067 PUD 102353067 PMD 0
>     Oops: 0000 [#1] PREEMPT SMP PTI
>     CPU: 1 PID: 1320 Comm: shmem-worker Kdump: loaded Not tainted 6.4.0-rc5+ #13
>     Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230301gitf80f052277c8-1.fc37 03/01/2023
>     RIP: 0010:trace_event_raw_event_writeback_folio_template+0x76/0xf0
>     Code: 4d 85 e4 74 5c 49 8b 3c 24 e8 06 98 ee ff 48 89 c7 e8 9e 8b ee ff ba 20 00 00 00 48 89 ef 48 89 c6 e8 fe d4 1a 00 49 8b 04 24 <48> 8b 40 40 48 89 43 28 49 8b 45 20 48 89 e7 48 89 43 30 e8 a2 4d
>     RSP: 0000:ffffaad580b6fb60 EFLAGS: 00010246
>     RAX: 0000000000000000 RBX: ffff90e38035c01c RCX: 0000000000000000
>     RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e38035c044
>     RBP: ffff90e38035c024 R08: 0000000000000002 R09: 0000000000000006
>     R10: ffff90e38035c02e R11: 0000000000000020 R12: ffff90e380bac000
>     R13: ffffe3a7456d9200 R14: 0000000000001b81 R15: ffffe3a7456d9200
>     FS:  00007f2e4e8a15c0(0000) GS:ffff90e3fbc80000(0000) knlGS:0000000000000000
>     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>     CR2: 0000000000000040 CR3: 00000001150c6003 CR4: 0000000000170ee0
>     Call Trace:
>      <TASK>
>      ? __die+0x20/0x70
>      ? page_fault_oops+0x76/0x170
>      ? kernelmode_fixup_or_oops+0x84/0x110
>      ? exc_page_fault+0x65/0x150
>      ? asm_exc_page_fault+0x22/0x30
>      ? trace_event_raw_event_writeback_folio_template+0x76/0xf0
>      folio_wait_writeback+0x6b/0x80
>      shmem_swapin_folio+0x24a/0x500
>      ? filemap_get_entry+0xe3/0x140
>      shmem_get_folio_gfp+0x36e/0x7c0
>      ? find_busiest_group+0x43/0x1a0
>      shmem_fault+0x76/0x2a0
>      ? __update_load_avg_cfs_rq+0x281/0x2f0
>      __do_fault+0x33/0x130
>      do_read_fault+0x118/0x160
>      do_pte_missing+0x1ed/0x2a0
>      __handle_mm_fault+0x566/0x630
>      handle_mm_fault+0x91/0x210
>      do_user_addr_fault+0x22c/0x740
>      exc_page_fault+0x65/0x150
>      asm_exc_page_fault+0x22/0x30
> 
> This problem arises from the fact that the repurposed writeback_dirty_page
> trace event code was written assuming that every pointer to mapping
> (struct address_space) would come from a file-mapped page-cache object,
> thus mapping->host would always be populated, and that was a valid case
> before commit 19343b5bdd16.  The swap-cache address space
> (swapper_spaces), however, doesn't populate its ->host (struct inode)
> pointer, thus leading to the crashes in the corner-case aforementioned.
> 
> commit 19343b5bdd16 ended up breaking the assignment of __entry->name and
> __entry->ino for the wait_on_page_writeback tracepoint -- both dependent
> on mapping->host carrying a pointer to a valid inode.  The assignment of
> __entry->name was fixed by commit 68f23b89067f ("memcg: fix a crash in
> wb_workfn when a device disappears"), and this commit fixes the remaining
> case, for __entry->ino.
> 
> Link: https://lkml.kernel.org/r/20230606233613.1290819-1-aquini@redhat.com
> Fixes: 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for wait_on_page_writeback()")
> Signed-off-by: Rafael Aquini <aquini@redhat.com>
> Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
> Cc: Aristeu Rozanski <aris@redhat.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Rafael Aquini <aquini@redhat.com>
> ---
>  include/trace/events/writeback.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

All now queued up, thanks.

greg k-h

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template
  2023-06-24 14:04   ` Greg KH
@ 2023-06-24 20:26     ` Rafael Aquini
  0 siblings, 0 replies; 4+ messages in thread
From: Rafael Aquini @ 2023-06-24 20:26 UTC (permalink / raw)
  To: Greg KH; +Cc: stable, Yafang Shao, Aristeu Rozanski, Andrew Morton

On Sat, Jun 24, 2023 at 04:04:38PM +0200, Greg KH wrote:
> On Fri, Jun 23, 2023 at 09:46:01AM -0400, Rafael Aquini wrote:
> > commit 54abe19e00cfcc5a72773d15cd00ed19ab763439 upstream.
> > 
> > When commit 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for
> > wait_on_page_writeback()") repurposed the writeback_dirty_page trace event
> > as a template to create its new wait_on_page_writeback trace event, it
> > ended up opening a window to NULL pointer dereference crashes due to the
> > (infrequent) occurrence of a race where an access to a page in the
> > swap-cache happens concurrently with the moment this page is being written
> > to disk and the tracepoint is enabled:
> > 
> >     BUG: kernel NULL pointer dereference, address: 0000000000000040
> >     #PF: supervisor read access in kernel mode
> >     #PF: error_code(0x0000) - not-present page
> >     PGD 800000010ec0a067 P4D 800000010ec0a067 PUD 102353067 PMD 0
> >     Oops: 0000 [#1] PREEMPT SMP PTI
> >     CPU: 1 PID: 1320 Comm: shmem-worker Kdump: loaded Not tainted 6.4.0-rc5+ #13
> >     Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS edk2-20230301gitf80f052277c8-1.fc37 03/01/2023
> >     RIP: 0010:trace_event_raw_event_writeback_folio_template+0x76/0xf0
> >     Code: 4d 85 e4 74 5c 49 8b 3c 24 e8 06 98 ee ff 48 89 c7 e8 9e 8b ee ff ba 20 00 00 00 48 89 ef 48 89 c6 e8 fe d4 1a 00 49 8b 04 24 <48> 8b 40 40 48 89 43 28 49 8b 45 20 48 89 e7 48 89 43 30 e8 a2 4d
> >     RSP: 0000:ffffaad580b6fb60 EFLAGS: 00010246
> >     RAX: 0000000000000000 RBX: ffff90e38035c01c RCX: 0000000000000000
> >     RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff90e38035c044
> >     RBP: ffff90e38035c024 R08: 0000000000000002 R09: 0000000000000006
> >     R10: ffff90e38035c02e R11: 0000000000000020 R12: ffff90e380bac000
> >     R13: ffffe3a7456d9200 R14: 0000000000001b81 R15: ffffe3a7456d9200
> >     FS:  00007f2e4e8a15c0(0000) GS:ffff90e3fbc80000(0000) knlGS:0000000000000000
> >     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >     CR2: 0000000000000040 CR3: 00000001150c6003 CR4: 0000000000170ee0
> >     Call Trace:
> >      <TASK>
> >      ? __die+0x20/0x70
> >      ? page_fault_oops+0x76/0x170
> >      ? kernelmode_fixup_or_oops+0x84/0x110
> >      ? exc_page_fault+0x65/0x150
> >      ? asm_exc_page_fault+0x22/0x30
> >      ? trace_event_raw_event_writeback_folio_template+0x76/0xf0
> >      folio_wait_writeback+0x6b/0x80
> >      shmem_swapin_folio+0x24a/0x500
> >      ? filemap_get_entry+0xe3/0x140
> >      shmem_get_folio_gfp+0x36e/0x7c0
> >      ? find_busiest_group+0x43/0x1a0
> >      shmem_fault+0x76/0x2a0
> >      ? __update_load_avg_cfs_rq+0x281/0x2f0
> >      __do_fault+0x33/0x130
> >      do_read_fault+0x118/0x160
> >      do_pte_missing+0x1ed/0x2a0
> >      __handle_mm_fault+0x566/0x630
> >      handle_mm_fault+0x91/0x210
> >      do_user_addr_fault+0x22c/0x740
> >      exc_page_fault+0x65/0x150
> >      asm_exc_page_fault+0x22/0x30
> > 
> > This problem arises from the fact that the repurposed writeback_dirty_page
> > trace event code was written assuming that every pointer to mapping
> > (struct address_space) would come from a file-mapped page-cache object,
> > thus mapping->host would always be populated, and that was a valid case
> > before commit 19343b5bdd16.  The swap-cache address space
> > (swapper_spaces), however, doesn't populate its ->host (struct inode)
> > pointer, thus leading to the crashes in the corner-case aforementioned.
> > 
> > commit 19343b5bdd16 ended up breaking the assignment of __entry->name and
> > __entry->ino for the wait_on_page_writeback tracepoint -- both dependent
> > on mapping->host carrying a pointer to a valid inode.  The assignment of
> > __entry->name was fixed by commit 68f23b89067f ("memcg: fix a crash in
> > wb_workfn when a device disappears"), and this commit fixes the remaining
> > case, for __entry->ino.
> > 
> > Link: https://lkml.kernel.org/r/20230606233613.1290819-1-aquini@redhat.com
> > Fixes: 19343b5bdd16 ("mm/page-writeback: introduce tracepoint for wait_on_page_writeback()")
> > Signed-off-by: Rafael Aquini <aquini@redhat.com>
> > Reviewed-by: Yafang Shao <laoar.shao@gmail.com>
> > Cc: Aristeu Rozanski <aris@redhat.com>
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> > Signed-off-by: Rafael Aquini <aquini@redhat.com>
> > ---
> >  include/trace/events/writeback.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> All now queued up, thanks.
>

Thank you, Greg.

-- Rafael


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-06-24 20:27 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-06-23  9:23 FAILED: patch "[PATCH] writeback: fix dereferencing NULL mapping->host on" failed to apply to 5.4-stable tree gregkh
2023-06-23 13:46 ` [PATCH 5.4.y] writeback: fix dereferencing NULL mapping->host on writeback_page_template Rafael Aquini
2023-06-24 14:04   ` Greg KH
2023-06-24 20:26     ` Rafael Aquini

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