On Tue, Sep 14, 2010 at 03:51:02PM +0300, Sergey Senozhatsky wrote: > Hello, > > This patch fixes NULL pointer dereference in print_daily_error_info, when > called > on unmounted fs (EXT4_SB(sb) returns NULL). Deleting error reporting timer > in > ext4_put_super fixes oops. Good catch! Thanks for the patch. I will include this into ext4 tree, and I will probably push it separately to Linus so that it gets into 2.6.36, since this is a regresssion. You didn't add a Signed-off-by: line, which is needed for Developer's Certification of Origin (see section 1, subsection 16 of Documentation/SubmittingPatches in the Linux source tree). Can you send confirmation that it's OK for me to add a Signed-off-by line for you? Thanks!! > By the way, isn't print_daily_error_info racy? Is it safe to call > print_daily_error_info > (by timer event (softirq)) when we'are remounting fs, etc.? It should be fine. Remounting doesn't actually change out the struct superblock. There is a chance that the information might not be fully complete if an error is printed exactly as the same time as print_daily_error_info() is run, but I'm not sure it's worth trying to protect against that race, since the worst that this will mean is a confusing report in the /var/log/messages file, and the ext4 error message will be printed right next to it, which will have all of the information the system administrator will need. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
