From 7e4ac11b6076e6a9bf7341ddeae22784284ed733 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Sat, 2 Mar 2024 06:58:57 +0200 Subject: [PATCH] getblkx(9): be more tolerant but also strict with the buffer size checks It is possible that on-disk filesystem format causes allocation of buffers of size larger than maxbcachebuf. Currently, getblkx() and indirectly bufkva_alloc() panic in that situation. It is more useful to return an error instead, allowing the system to continue running. PR: 277414 Reported by: Robert Morris MFC after: 1 week Sponsored by: The FreeBSD Foundation --- sys/kern/vfs_bio.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/sys/kern/vfs_bio.c b/sys/kern/vfs_bio.c index 4e0832475c3e..b5466fb2cd53 100644 --- a/sys/kern/vfs_bio.c +++ b/sys/kern/vfs_bio.c @@ -3985,9 +3985,11 @@ getblkx(struct vnode *vp, daddr_t blkno, daddr_t dblkno, int size, int slpflag, ("GB_KVAALLOC only makes sense with GB_UNMAPPED")); if (vp->v_type != VCHR) ASSERT_VOP_LOCKED(vp, "getblk"); - if (size > maxbcachebuf) - panic("getblk: size(%d) > maxbcachebuf(%d)\n", size, + if (size > maxbcachebuf) { + printf("getblkx: size(%d) > maxbcachebuf(%d)\n", size, maxbcachebuf); + return (EIO); + } if (!unmapped_buf_allowed) flags &= ~(GB_UNMAPPED | GB_KVAALLOC); @@ -4161,6 +4163,12 @@ newbuf_unlocked: vmio = vp->v_object != NULL; if (vmio) { maxsize = size + (offset & PAGE_MASK); + if (maxsize > maxbcachebuf) { + printf( + "getblkx: maxsize(%d) > maxbcachebuf(%d)\n", + maxsize, maxbcachebuf); + return (EIO); + } } else { maxsize = size; /* Do not allow non-VMIO notmapped buffers. */