| Message ID | ef914dfe-c2e7-7a8d-eaa7-4c087764bebc@groessler.org |
|---|---|
| State | New |
| Headers | show |
Hi, On Wed, Dec 07, 2016 at 01:22:00AM +0100, Christian Groessler wrote: > Hi, > > the attached patch prevents a crash when trying to mount a corrupted ext4 > file system. Why isn't it a backport of the equivalent mainline commit ? Is mainline not affected by the same bug ? Unless this is the case (and the mainline commit which made this one unnecessary) all fixes must go to mainline first before being backported to stable. > regards, > chris > Thanks, Willy --- > >From 86344aebe7e3905b2293a7891a68def8cb38a571 Mon Sep 17 00:00:00 2001 > From: Christian Groessler <chris@groessler.org> > Date: Wed, 7 Dec 2016 00:54:03 +0100 > Subject: [PATCH] Fix kernel crash when trying to mount corrupted ext4 > partition. > > ext4_calculate_overhead(), if successful, sets the 'ret' vatiable to 0. > Subsequent failures will bail out, with the function returning the 'ret' > variable as status. Since 'ret' is 0 (indicating no error) the kernel > will happily continue and eventually crash. > > This change preserves the value of 'ret' across the call to > ext4_calculate_overhead() in case this function doesn't return an > error. > > Signed-off-by: Christian Groessler <chris@groessler.org> > --- > fs/ext4/super.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 5862518..0f63644 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3692,9 +3692,12 @@ no_journal: > if (es->s_overhead_clusters) > sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters); > else { > + int oret = ret; > ret = ext4_calculate_overhead(sb); > if (ret) > goto failed_mount_wq; > + else > + ret = oret; > } > > /* > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Dec 07, 2016 at 01:22:00AM +0100, Christian Groessler wrote: > Hi, > > the attached patch prevents a crash when trying to mount a corrupted ext4 > file system. <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. </formletter> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On 12/07/16 07:30, Willy Tarreau wrote: > On Wed, Dec 07, 2016 at 01:22:00AM +0100, Christian Groessler wrote: >> Hi, >> >> the attached patch prevents a crash when trying to mount a corrupted ext4 >> file system. > Why isn't it a backport of the equivalent mainline commit ? Good question. > Is mainline > not affected by the same bug ? The bug was fixed in mainline with commit 07aa2ea13814e. I will backport that and resubmit. regards, chris -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From 86344aebe7e3905b2293a7891a68def8cb38a571 Mon Sep 17 00:00:00 2001 From: Christian Groessler <chris@groessler.org> Date: Wed, 7 Dec 2016 00:54:03 +0100 Subject: [PATCH] Fix kernel crash when trying to mount corrupted ext4 partition. ext4_calculate_overhead(), if successful, sets the 'ret' vatiable to 0. Subsequent failures will bail out, with the function returning the 'ret' variable as status. Since 'ret' is 0 (indicating no error) the kernel will happily continue and eventually crash. This change preserves the value of 'ret' across the call to ext4_calculate_overhead() in case this function doesn't return an error. Signed-off-by: Christian Groessler <chris@groessler.org> --- fs/ext4/super.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 5862518..0f63644 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3692,9 +3692,12 @@ no_journal: if (es->s_overhead_clusters) sbi->s_overhead = le32_to_cpu(es->s_overhead_clusters); else { + int oret = ret; ret = ext4_calculate_overhead(sb); if (ret) goto failed_mount_wq; + else + ret = oret; } /* -- 2.7.4