diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-13 16:51:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 18:38:29 -0700 |
| commit | 853322a671047f9300b9ccc2c358af2859bca2c2 (patch) | |
| tree | f13a90a949ca24ebd21012e875f97a00cff061e6 | |
| parent | 8490e2e25b5a1f9591145f0e3bbd09b99409be76 (diff) | |
mm/debug.c: do not dereference i_ino blindly
__dump_page() checks i_dentry is fetchable and i_ino is earlier in the
struct than i_ino, so it ought to work fine, but it's possible that struct
randomisation has reordered i_ino after i_dentry and the pointer is just
wild enough that i_dentry is fetchable and i_ino isn't.
Also print the inode number if the dentry is invalid.
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lkml.kernel.org/r/20200819185710.28180-1-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/debug.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/mm/debug.c b/mm/debug.c index ca8d1cacdecc..2a767865145c 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -120,6 +120,7 @@ void __dump_page(struct page *page, const char *reason) struct hlist_node *dentry_first; struct dentry *dentry_ptr; struct dentry dentry; + unsigned long ino; /* * mapping can be invalid pointer and we don't want to crash @@ -136,21 +137,22 @@ void __dump_page(struct page *page, const char *reason) goto out_mapping; } - if (get_kernel_nofault(dentry_first, &host->i_dentry.first)) { + if (get_kernel_nofault(dentry_first, &host->i_dentry.first) || + get_kernel_nofault(ino, &host->i_ino)) { pr_warn("aops:%ps with invalid host inode %px\n", a_ops, host); goto out_mapping; } if (!dentry_first) { - pr_warn("aops:%ps ino:%lx\n", a_ops, host->i_ino); + pr_warn("aops:%ps ino:%lx\n", a_ops, ino); goto out_mapping; } dentry_ptr = container_of(dentry_first, struct dentry, d_u.d_alias); if (get_kernel_nofault(dentry, dentry_ptr)) { - pr_warn("aops:%ps with invalid dentry %px\n", a_ops, - dentry_ptr); + pr_warn("aops:%ps ino:%lx with invalid dentry %px\n", + a_ops, ino, dentry_ptr); } else { /* * if dentry is corrupted, the %pd handler may still @@ -158,7 +160,7 @@ void __dump_page(struct page *page, const char *reason) * corrupted struct page */ pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", - a_ops, host->i_ino, &dentry); + a_ops, ino, &dentry); } } out_mapping: |