user/sven/linux.git/fs/sysfs, branch stable/3.4.y

sysfs: fix use after free in case of concurrent read/write and readdir

2013-05-08T02:51:54Z

commit f7db5e7660b122142410dcf36ba903c73d473250 upstream. The inode->i_mutex isn't hold when updating filp->f_pos in read()/write(), so the filp->f_pos might be read as 0 or 1 in readdir() when there is concurrent read()/write() on this same file, then may cause use after free in readdir(). The bug can be reproduced with Li Zefan's test code on the link: https://patchwork.kernel.org/patch/2160771/ This patch fixes the use after free under this situation. Reported-by: Li Zefan Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman

sysfs: handle failure path correctly for readdir()

2013-04-05T17:04:16Z

commit e5110f411d2ee35bf8d202ccca2e89c633060dca upstream. In case of 'if (filp->f_pos == 0 or 1)' of sysfs_readdir(), the failure from filldir() isn't handled, and the reference counter of the sysfs_dirent object pointed by filp->private_data will be released without clearing filp->private_data, so use after free bug will be triggered later. This patch returns immeadiately under the situation for fixing the bug, and it is reasonable to return from readdir() when filldir() fails. Reported-by: Dave Jones Tested-by: Sasha Levin Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman

sysfs: fix race between readdir and lseek

2013-04-05T17:04:16Z

commit 991f76f837bf22c5bb07261cfd86525a0a96650c upstream. While readdir() is running, lseek() may set filp->f_pos as zero, then may leave filp->private_data pointing to one sysfs_dirent object without holding its reference counter, so the sysfs_dirent object may be used after free in next readdir(). This patch holds inode->i_mutex to avoid the problem since the lock is always held in readdir path. Reported-by: Dave Jones Tested-by: Sasha Levin Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman

sysfs: sysfs_pathname/sysfs_add_one: Use strlcat() instead of strcat()

2012-10-31T17:02:57Z

commit 66081a72517a131430dcf986775f3268aafcb546 upstream. The warning check for duplicate sysfs entries can cause a buffer overflow when printing the warning, as strcat() doesn't check buffer sizes. Use strlcat() instead. Since strlcat() doesn't return a pointer to the passed buffer, unlike strcat(), I had to convert the nested concatenation in sysfs_add_one() to an admittedly more obscure comma operator construct, to avoid emitting code for the concatenation if CONFIG_BUG is disabled. Signed-off-by: Geert Uytterhoeven Signed-off-by: Greg Kroah-Hartman

sysfs: handle 'parent deleted before child added'

2012-04-10T21:48:51Z

In scsi at least two cases of the parent device being deleted before the child is added have been observed. 1/ scsi is performing async scans and the device is removed prior to the async can thread running (can happen with an in-opportune / unlikely unplug during initial scan). 2/ libsas discovery event running after the parent port has been torn down (this is a bug in libsas). Result in crash signatures like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [] sysfs_create_dir+0x32/0xb6 ... Process scsi_scan_8 (pid: 5417, threadinfo ffff88080bd16000, task ffff880801b8a0b0) Stack: 00000000fffffffe ffff880813470628 ffff88080bd17cd0 ffff88080614b7e8 ffff88080b45c108 00000000fffffffe ffff88080bd17d20 ffffffff8125e4a8 ffff88080bd17cf0 ffffffff81075149 ffff88080bd17d30 ffff88080614b7e8 Call Trace: [] kobject_add_internal+0x120/0x1e3 [] ? trace_hardirqs_on+0xd/0xf [] kobject_add_varg+0x41/0x50 [] kobject_add+0x64/0x66 [] device_add+0x12d/0x63a In this scenario the parent is still valid (because we have a reference), but it has been device_del()'d which means its kobj->sd pointer is NULL'd via: device_del()->kobject_del()->sysfs_remove_dir() ...and then sysfs_create_dir() (without this fix) goes ahead and de-references parent_sd via sysfs_ns_type(): return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT; This scenario is being fixed in scsi/libsas, but if other subsystems present the same ordering the system need not immediately crash. Cc: Greg Kroah-Hartman Cc: James Bottomley Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

sysfs: Prevent crash on unset sysfs group attributes

2012-04-10T21:48:51Z

Do not let the kernel crash when a device is registered with sysfs while group attributes are not set (aka NULL). Warn about the offender with some information about the offending device. This would warn instead of trying NULL pointer deref like: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] internal_create_group+0x83/0x1a0 PGD 0 Oops: 0000 [#1] SMP CPU 0 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc1-x86_64 #3 HP ProLiant DL360 G4 RIP: 0010:[] [] internal_create_group+0x83/0x1a0 RSP: 0018:ffff88019485fd70 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffff880192e99908 RSI: ffff880192e99630 RDI: ffffffff81a26c60 RBP: ffff88019485fdc0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff880192e99908 R11: 0000000000000000 R12: ffffffff81a16a00 R13: ffff880192e99908 R14: ffffffff81a16900 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88019bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001a0c000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper/0 (pid: 1, threadinfo ffff88019485e000, task ffff880194878000) Stack: ffff88019485fdd0 ffff880192da9d60 0000000000000000 ffff880192e99908 ffff880192e995d8 0000000000000001 ffffffff81a16a00 ffff880192da9d60 0000000000000000 0000000000000000 ffff88019485fdd0 ffffffff811527be Call Trace: [] sysfs_create_group+0xe/0x10 [] device_add_groups+0x46/0x80 [] device_add+0x46d/0x6a0 ... Signed-off-by: Bruno Prémont Acked-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

sysfs: Update the name hash for an entry after changing the namespace

2012-04-09T22:33:00Z

This is needed to allow renaming network devices that have been moved to another network namespace. Signed-off-by: Tom Goff Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2012-03-21T20:36:41Z

Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...

switch open-coded instances of d_make_root() to new helper

2012-03-21T01:29:35Z

Signed-off-by: Al Viro

Revert "sysfs: Kill nlink counting."

2012-03-08T21:03:10Z

This reverts commit 524b6c5b39b931311dfe5a2f5abae2f5c9731676. It has shown to break userspace tools, which is not acceptable. Reported-by: Jiri Slaby Cc: Eric W. Biederman Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman