5.4-stable review patch. If anyone has any objections, please let me know.
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From: Osama Muhammad osmtendev@gmail.com
[ Upstream commit 8877243beafa7c6bfc42022cbfdf9e39b25bd4fa ]
Syzkaller has reported a NULL pointer dereference when accessing rgd->rd_rgl in gfs2_rgrp_dump(). This can happen when creating rgd->rd_gl fails in read_rindex_entry(). Add a NULL pointer check in gfs2_rgrp_dump() to prevent that.
Reported-and-tested-by: syzbot+da0fc229cc1ff4bb2e6d@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=da0fc229cc1ff4bb2e6d Fixes: 72244b6bc752 ("gfs2: improve debug information when lvb mismatches are found") Signed-off-by: Osama Muhammad osmtendev@gmail.com Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/gfs2/rgrp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 8153a3eac540..f0a135a48cc3 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -2275,7 +2275,7 @@ void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_glock *gl, (unsigned long long)rgd->rd_addr, rgd->rd_flags, rgd->rd_free, rgd->rd_free_clone, rgd->rd_dinodes, rgd->rd_reserved, rgd->rd_extfail_pt); - if (rgd->rd_sbd->sd_args.ar_rgrplvb) { + if (rgd->rd_sbd->sd_args.ar_rgrplvb && rgd->rd_rgl) { struct gfs2_rgrp_lvb *rgl = rgd->rd_rgl;
gfs2_print_dbg(seq, "%s L: f:%02x b:%u i:%u\n", fs_id_buf,