Date: Thu, 08 Oct 2015 18:33:23 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 203644] makefs: Coverity CID 974635, 974636: Copying several struct elements by single memcpy(). Message-ID: <bug-203644-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=203644 Bug ID: 203644 Summary: makefs: Coverity CID 974635, 974636: Copying several struct elements by single memcpy(). Product: Base System Version: 11.0-CURRENT Hardware: Any OS: Any Status: New Severity: Affects Some People Priority: --- Component: bin Assignee: freebsd-bugs@FreeBSD.org Reporter: scdbackup@gmx.net usr.sbin/makefs/ffs/ffs_bswap.c CID 974635 : Destination buffer too small (BUFFER_SIZE) 10. buffer_size: You might overrun the 48 byte destination string n->di_db by writing the maximum 60 bytes from o->di_db. 138 memcpy(n->di_db, o->di_db, (NDADDR + NIADDR) * sizeof(u_int32_t)); CID 974636 : Destination buffer too small (BUFFER_SIZE) 20. buffer_size: You might overrun the 16 byte destination string n->di_extb by writing the maximum 136 bytes from o->di_extb. 168 memcpy(n->di_extb, o->di_extb, (NXADDR + NDADDR + NIADDR) * 8); --------------- Source analysis: sys/ufs/ufs/dinode.h defines typedef int32_t ufs1_daddr_t; ... struct ufs1_dinode { ... ufs1_daddr_t di_db[NDADDR]; /* 40: Direct disk blocks. */ ufs1_daddr_t di_ib[NIADDR]; /* 88: Indirect disk blocks. */ ... So both arrays get copied in one memcpy() operation. Same with CID 974636: typedef int64_t ufs2_daddr_t; ... struct ufs2_dinode { ... ufs2_daddr_t di_extb[NXADDR];/* 96: External attributes block. */ ufs2_daddr_t di_db[NDADDR]; /* 112: Direct disk blocks. */ ufs2_daddr_t di_ib[NIADDR]; /* 208: Indirect disk blocks. */ Three arrays, one memcpy(). --------------- Remedy proposal: One should consider to use two or three separate memcpy() calls. (I cannot judge whether the alignment of 40 and 88 needs padding bytes on any architecture.) -- You are receiving this mail because: You are the assignee for the bug.
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