From: Darrick J. Wong Date: Fri, 27 May 2022 00:22:56 +0000 (+1000) Subject: xfs: don't leak btree cursor when insrec fails after a split X-Git-Tag: v6.6.17~7370^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a54f78def73d847cb060b18c4e4a3d1d26c9ca6d;p=platform%2Fkernel%2Flinux-rpi.git xfs: don't leak btree cursor when insrec fails after a split The recent patch to improve btree cycle checking caused a regression when I rebased the in-memory btree branch atop the 5.19 for-next branch, because in-memory short-pointer btrees do not have AG numbers. This produced the following complaint from kmemleak: unreferenced object 0xffff88803d47dde8 (size 264): comm "xfs_io", pid 4889, jiffies 4294906764 (age 24.072s) hex dump (first 32 bytes): 90 4d 0b 0f 80 88 ff ff 00 a0 bd 05 80 88 ff ff .M.............. e0 44 3a a0 ff ff ff ff 00 df 08 06 80 88 ff ff .D:............. backtrace: [] xfbtree_dup_cursor+0x49/0xc0 [xfs] [] xfs_btree_dup_cursor+0x3b/0x200 [xfs] [] __xfs_btree_split+0x6ad/0x820 [xfs] [] xfs_btree_split+0x60/0x110 [xfs] [] xfs_btree_make_block_unfull+0x19a/0x1f0 [xfs] [] xfs_btree_insrec+0x3aa/0x810 [xfs] [] xfs_btree_insert+0xb3/0x240 [xfs] [] xfs_rmap_insert+0x99/0x200 [xfs] [] xfs_rmap_map_shared+0x192/0x5f0 [xfs] [] xfs_rmap_map_raw+0x6b/0x90 [xfs] [] xrep_rmap_stash+0xd5/0x1d0 [xfs] [] xrep_rmap_visit_bmbt+0xa0/0xf0 [xfs] [] xrep_rmap_scan_iext+0x56/0xa0 [xfs] [] xrep_rmap_scan_ifork+0xd8/0x160 [xfs] [] xrep_rmap_scan_inode+0x35/0x80 [xfs] [] xrep_rmap_find_rmaps+0x10e/0x270 [xfs] I noticed that xfs_btree_insrec has a bunch of debug code that return out of the function immediately, without freeing the "new" btree cursor that can be returned when _make_block_unfull calls xfs_btree_split. Fix the error return in this function to free the btree cursor. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c index 32100cf..2eecc49 100644 --- a/fs/xfs/libxfs/xfs_btree.c +++ b/fs/xfs/libxfs/xfs_btree.c @@ -3272,7 +3272,7 @@ xfs_btree_insrec( struct xfs_btree_block *block; /* btree block */ struct xfs_buf *bp; /* buffer for block */ union xfs_btree_ptr nptr; /* new block ptr */ - struct xfs_btree_cur *ncur; /* new btree cursor */ + struct xfs_btree_cur *ncur = NULL; /* new btree cursor */ union xfs_btree_key nkey; /* new block key */ union xfs_btree_key *lkey; int optr; /* old key/record index */ @@ -3352,7 +3352,7 @@ xfs_btree_insrec( #ifdef DEBUG error = xfs_btree_check_block(cur, block, level, bp); if (error) - return error; + goto error0; #endif /* @@ -3372,7 +3372,7 @@ xfs_btree_insrec( for (i = numrecs - ptr; i >= 0; i--) { error = xfs_btree_debug_check_ptr(cur, pp, i, level); if (error) - return error; + goto error0; } xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1); @@ -3457,6 +3457,8 @@ xfs_btree_insrec( return 0; error0: + if (ncur) + xfs_btree_del_cursor(ncur, error); return error; }