Messages in this thread Patch in this message | | | Date | Mon, 27 Oct 2008 20:44:31 +0900 | From | Hidehiro Kawai <> | Subject | [PATCH 1/2 take 2] ext3: fix a bug accessing freed memory in ext3_abort |
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Ingo Molnar wrote:
> * Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> wrote: > >>Vegard Nossum reported a bug which accesses freed memory. When >>journal has been aborted, ext4_put_super() calls ext4_abort() after >>freeing the journal_t object, and then ext4_abort() accesses it. >>This patch fix it. >> >>Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> > > could you please put the word "kmemcheck" into the commit log? ("found > via kmemcheck" or so) We want to have an easily git-greppable track > record of upstream kernel bugs that were found via kmemcheck. (and > there's already a long list)
Ah, OK. I fixed the commit log.
Thanks,
Subject: [PATCH 1/2] ext3: fix a bug accessing freed memory in ext3_abort
Vegard Nossum reported a bug which accesses freed memory (found via kmemcheck). When journal has been aborted, ext3_put_super() calls ext3_abort() after freeing the journal_t object, and then ext3_abort() accesses it. This patch fix it.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Jan Kara <jack@suse.cz> --- fs/ext3/super.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
Index: linux-2.6.28-rc2/fs/ext3/super.c =================================================================== --- linux-2.6.28-rc2.orig/fs/ext3/super.c +++ linux-2.6.28-rc2/fs/ext3/super.c @@ -281,7 +281,8 @@ void ext3_abort (struct super_block * sb EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS; sb->s_flags |= MS_RDONLY; EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT; - journal_abort(EXT3_SB(sb)->s_journal, -EIO); + if (EXT3_SB(sb)->s_journal) + journal_abort(EXT3_SB(sb)->s_journal, -EIO); } void ext3_warning (struct super_block * sb, const char * function, @@ -390,11 +391,14 @@ static void ext3_put_super (struct super { struct ext3_sb_info *sbi = EXT3_SB(sb); struct ext3_super_block *es = sbi->s_es; - int i; + int i, err; ext3_xattr_put_super(sb); - if (journal_destroy(sbi->s_journal) < 0) + err = journal_destroy(sbi->s_journal); + sbi->s_journal = NULL; + if (err < 0) ext3_abort(sb, __func__, "Couldn't clean up the journal"); + if (!(sb->s_flags & MS_RDONLY)) { EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER); es->s_state = cpu_to_le16(sbi->s_mount_state);
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