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Groups > linux.kernel > #1251218
| From | lizf@kernel.org |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.4 64/65] dcache: Handle escaped paths in prepend_path |
| Date | 2015-10-20 03:00 +0200 |
| Message-ID | <qltrt-4x1-55@gated-at.bofh.it> (permalink) |
| References | <qlthL-4kA-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: "Eric W. Biederman" <ebiederm@xmission.com>
3.4.110-rc1 review patch. If anyone has any objections, please let me know.
------------------
commit cde93be45a8a90d8c264c776fab63487b5038a65 upstream.
A rename can result in a dentry that by walking up d_parent
will never reach it's mnt_root. For lack of a better term
I call this an escaped path.
prepend_path is called by four different functions __d_path,
d_absolute_path, d_path, and getcwd.
__d_path only wants to see paths are connected to the root it passes
in. So __d_path needs prepend_path to return an error.
d_absolute_path similarly wants to see paths that are connected to
some root. Escaped paths are not connected to any mnt_root so
d_absolute_path needs prepend_path to return an error greater
than 1. So escaped paths will be treated like paths on lazily
unmounted mounts.
getcwd needs to prepend "(unreachable)" so getcwd also needs
prepend_path to return an error.
d_path is the interesting hold out. d_path just wants to print
something, and does not care about the weird cases. Which raises
the question what should be printed?
Given that <escaped_path>/<anything> should result in -ENOENT I
believe it is desirable for escaped paths to be printed as empty
paths. As there are not really any meaninful path components when
considered from the perspective of a mount tree.
So tweak prepend_path to return an empty path with an new error
code of 3 when it encounters an escaped path.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Zefan Li <lizefan@huawei.com>
---
fs/dcache.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/fs/dcache.c b/fs/dcache.c
index d071ea7..03eb2c2 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2518,6 +2518,8 @@ static int prepend_path(const struct path *path,
struct dentry *dentry = path->dentry;
struct vfsmount *vfsmnt = path->mnt;
struct mount *mnt = real_mount(vfsmnt);
+ char *orig_buffer = *buffer;
+ int orig_len = *buflen;
bool slash = false;
int error = 0;
@@ -2525,6 +2527,14 @@ static int prepend_path(const struct path *path,
struct dentry * parent;
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
+ /* Escaped? */
+ if (dentry != vfsmnt->mnt_root) {
+ *buffer = orig_buffer;
+ *buflen = orig_len;
+ slash = false;
+ error = 3;
+ goto global_root;
+ }
/* Global root? */
if (!mnt_has_parent(mnt))
goto global_root;
--
1.9.1
--
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[PATCH 3.4 00/65] 3.4.110-rc1 review lizf@kernel.org - 2015-10-20 02:50 +0200
[PATCH 3.4 16/65] usb: core: Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset lizf@kernel.org - 2015-10-20 02:50 +0200
[PATCH 3.4 50/65] crush: fix a bug in tree bucket decode lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 54/65] KVM: x86: properly restore LVT0 lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 56/65] Revert "drm/i915: Don't skip request retirement if the active list is empty" lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 43/65] stmmac: troubleshoot unexpected bits in des0 & des1 lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 35/65] nfs: increase size of EXCHANGE_ID name string buffer lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 55/65] 9p: forgetting to cancel request on interrupted zero-copy RPC lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 46/65] tracing/filter: Do not WARN on operand count going below zero lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 61/65] usb: dwc3: Reset the transfer resource index on SET_INTERFACE lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 24/65] x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 44/65] mm: kmemleak: allow safe memory scanning during kmemleak disabling lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 23/65] regulator: core: fix constraints output buffer lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 60/65] ARM: Fix incorrect backport of 0b59d8806a31 lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 40/65] ext4: don't retry file block mapping on bigalloc fs with non-extent file lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 30/65] jbd2: use GFP_NOFS in jbd2_cleanup_journal_tail() lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 63/65] IB/qib: Change lkey table allocation to support more MRs lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 65/65] vfs: Test for and handle paths that are unreachable from their mnt_root lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 62/65] jbd2: avoid infinite loop when destroying aborted journal lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 37/65] ext4: call sync_blockdev() before invalidate_bdev() in put_super() lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 48/65] __bitmap_parselist: fix bug in empty string handling lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 59/65] crypto: s390/ghash: Fix incorrect backport of a1cae34e23b1 lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 47/65] tracing/filter: Do not allow infix to exceed end of string lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 58/65] drm/radeon: partially revert "fix VM_CONTEXT*_PAGE_TABLE_END_ADDR handling" lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 52/65] ACPICA: Tables: Fix an issue that FACS initialization is performed twice lizf@kernel.org - 2015-10-20 03:00 +0200
RE: [PATCH 3.4 52/65] ACPICA: Tables: Fix an issue that FACS initialization is performed twice "Moore, Robert" <robert.moore@intel.com> - 2015-10-20 15:40 +0200
RE: [PATCH 3.4 52/65] ACPICA: Tables: Fix an issue that FACS initialization is performed twice "Zheng, Lv" <lv.zheng@intel.com> - 2015-10-21 03:30 +0200
[PATCH 3.4 53/65] KVM: x86: make vapics_in_nmi_mode atomic lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 34/65] mmc: card: Fixup request missing in mmc_blk_issue_rw_rq lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 42/65] bridge: multicast: restore router configuration on port link down/up lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 64/65] dcache: Handle escaped paths in prepend_path lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 36/65] bridge: fix br_stp_set_bridge_priority race conditions lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 51/65] fuse: initialize fc->release before calling it lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 38/65] packet: read num_members once in packet_rcv_fanout() lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 57/65] Revert "drm/radeon: Use drm_calloc_ab for CS relocs" lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 49/65] agp/intel: Fix typo in needs_ilk_vtd_wa() lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 27/65] ext4: fix race between truncate and __ext4_journalled_writepage() lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 39/65] packet: avoid out of bounds read in round robin fanout lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 45/65] dell-laptop: Fix allocating & freeing SMI buffer page lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 41/65] watchdog: omap: assert the counter being stopped before reprogramming lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 25/65] dmaengine: mv_xor: bug fix for racing condition in descriptors cleanup lizf@kernel.org - 2015-10-20 03:00 +0200
[PATCH 3.4 33/65] ideapad: fix software rfkill setting lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 19/65] SUNRPC: Fix a memory leak in the backchannel code lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 10/65] rndis_wlan: harmless issue calling set_bit() lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 32/65] jbd2: fix ocfs2 corrupt when updating journal superblock fails lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 12/65] usb: dwc3: gadget: return error if command sent to DEPCMD register fails lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 20/65] ipr: Increase default adapter init stage change timeout lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 26/65] ASoC: wm8960: the enum of "DAC Polarity" should be wm8960_enum[1] lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 06/65] ASoC: wm8955: Fix setting wrong register for WM8955_K_8_0_MASK bits lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 01/65] hrtimer: Allow concurrent hrtimer_start() for self restarting timers lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 09/65] tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 28/65] Disable write buffering on Toshiba ToPIC95 lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 13/65] rcu: Correctly handle non-empty Tiny RCU callback list with none ready lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 22/65] ath9k: fix DMA stop sequence for AR9003+ lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 31/65] regmap: Fix regmap_bulk_read in BE mode lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 15/65] staging: rtl8712: prevent buffer overrun in recvbuf2recvframe lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 02/65] mtd: fix: avoid race condition when accessing mtd->usecount lizf@kernel.org - 2015-10-20 03:10 +0200
[PATCH 3.4 29/65] sctp: fix ASCONF list handling lizf@kernel.org - 2015-10-20 03:10 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-10-20 04:20 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Geert Uytterhoeven <geert@linux-m68k.org> - 2015-10-20 09:10 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Geert Uytterhoeven <geert@linux-m68k.org> - 2015-10-20 11:10 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-10-20 15:00 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Guenter Roeck <linux@roeck-us.net> - 2015-10-20 15:20 +0200
Re: [PATCH 3.4 00/65] 3.4.110-rc1 review Zefan Li <lizefan@huawei.com> - 2015-10-21 10:10 +0200
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