From de5fe95587b4dcc86cc451fce2909dfa504fce10 Mon Sep 17 00:00:00 2001 From: Lingzhu Xiang Date: Sat, 5 Jan 2013 13:59:52 +0800 Subject: efivarfs: Drop link count of the right inode efivarfs_unlink() should drop the file's link count, not the directory's. Signed-off-by: Lingzhu Xiang Cc: Jeremy Kerr Tested-by: Lee, Chun-Yi Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 7b1c37497c9..fa9fa038de3 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -994,7 +994,7 @@ static int efivarfs_unlink(struct inode *dir, struct dentry *dentry) list_del(&var->list); spin_unlock(&efivars->lock); efivar_unregister(var); - drop_nlink(dir); + drop_nlink(dentry->d_inode); dput(dentry); return 0; } -- cgit v1.2.3 From 1fa7e6958c5f82cc75c594e3ffaf73cc26fc94c1 Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Wed, 16 Jan 2013 13:47:05 +0000 Subject: efivarfs: Never return ENOENT from firmware Files are created in efivarfs_create() before a corresponding variable is created in the firmware. This leads to users being able to read/write to the file without the variable existing in the firmware. Reading a non-existent variable currently returns -ENOENT, which is confusing because the file obviously *does* exist. Convert EFI_NOT_FOUND into -EIO which is the closest thing to "error while interacting with firmware", and should hopefully indicate to the caller that the variable is in some uninitialised state. Cc: Josh Boyer Acked-by: Jeremy Kerr Cc: Lee, Chun-Yi Cc: Andy Whitcroft Reported-by: Lingzhu Xiang Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index fa9fa038de3..807dad48b2b 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -674,7 +674,7 @@ static int efi_status_to_err(efi_status_t status) err = -EACCES; break; case EFI_NOT_FOUND: - err = -ENOENT; + err = -EIO; break; default: err = -EINVAL; -- cgit v1.2.3 From 791eb564d218dabe0f9a2212916fe54240b97afb Mon Sep 17 00:00:00 2001 From: Matt Fleming Date: Wed, 16 Jan 2013 21:55:36 +0000 Subject: efivarfs: Delete dentry from dcache in efivarfs_file_write() Unlike the unlink path that is called from the VFS layer, we need to call d_delete() ourselves when a variable is deleted in efivarfs_file_write(). Failure to do so means we can access a stale struct efivar_entry when reading/writing the file, which can result in the following oops, [ 59.978216] general protection fault: 0000 [#1] SMP [ 60.038660] CPU 9 [ 60.040501] Pid: 1001, comm: cat Not tainted 3.7.0-2.fc19.x86_64 #1 IBM System x3550 M3 -[7944I21]-/69Y4438 [ 60.050840] RIP: 0010:[] [] __lock_acquire+0x5e/0x1bb0 [ 60.059198] RSP: 0018:ffff880270595ce8 EFLAGS: 00010046 [ 60.064500] RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000000 [ 60.071617] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 6b6b6b6b6b6b6b83 [ 60.078735] RBP: ffff880270595dd8 R08: 0000000000000002 R09: 0000000000000000 [ 60.085852] R10: 6b6b6b6b6b6b6b83 R11: 0000000000000000 R12: 0000000000000000 [ 60.092971] R13: ffff88027170cd20 R14: 0000000000000000 R15: 0000000000000000 [ 60.100091] FS: 00007fc0c8ff3740(0000) GS:ffff880277000000(0000) knlGS:0000000000000000 [ 60.108164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.113899] CR2: 0000000001520000 CR3: 000000026d594000 CR4: 00000000000007e0 [ 60.121016] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 60.128135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 60.135254] Process cat (pid: 1001, threadinfo ffff880270594000, task ffff88027170cd20) [ 60.143239] Stack: [ 60.145251] ffff880270595cf8 ffffffff81021da3 ffff880270595d08 ffffffff81021e19 [ 60.152714] ffff880270595d38 ffffffff810acdb5 ffff880200000168 0000000000000086 [ 60.160175] ffff88027170d5e8 ffffffff810d25ed ffff880270595d58 ffffffff810ace7f [ 60.167638] Call Trace: [ 60.170088] [] ? native_sched_clock+0x13/0x80 [ 60.176085] [] ? sched_clock+0x9/0x10 [ 60.181389] [] ? sched_clock_cpu+0xc5/0x120 [ 60.187211] [] ? trace_hardirqs_off+0xd/0x10 [ 60.193121] [] ? local_clock+0x6f/0x80 [ 60.198513] [] ? lock_release_holdtime.part.26+0xf/0x180 [ 60.205465] [] ? lock_release_non_nested+0x2e7/0x320 [ 60.212073] [] ? efivarfs_file_write+0x5b/0x280 [ 60.218242] [] lock_acquire+0xa1/0x1f0 [ 60.223633] [] ? efivarfs_file_write+0x111/0x280 [ 60.229892] [] ? might_fault+0x5c/0xb0 [ 60.235287] [] _raw_spin_lock+0x46/0x80 [ 60.240762] [] ? efivarfs_file_write+0x111/0x280 [ 60.247018] [] efivarfs_file_write+0x111/0x280 [ 60.253103] [] vfs_write+0xaf/0x190 [ 60.258233] [] sys_write+0x55/0xa0 [ 60.263278] [] system_call_fastpath+0x16/0x1b [ 60.269271] Code: 41 0f 45 d8 4c 89 75 f0 4c 89 7d f8 85 c0 0f 84 09 01 00 00 8b 05 a3 f9 ff 00 49 89 fa 41 89 f6 41 89 d3 85 c0 0f 84 12 01 00 00 <49> 8b 02 ba 01 00 00 00 48 3d a0 07 14 82 0f 44 da 41 83 fe 01 [ 60.289431] RIP [] __lock_acquire+0x5e/0x1bb0 [ 60.295444] RSP [ 60.298928] ---[ end trace 1bbfd41a2cf6a0d8 ]--- Cc: Josh Boyer Acked-by: Jeremy Kerr Cc: Lee, Chun-Yi Cc: Andy Whitcroft Reported-by: Lingzhu Xiang Signed-off-by: Matt Fleming --- drivers/firmware/efivars.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/firmware') diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c index 807dad48b2b..2ed59dc1c48 100644 --- a/drivers/firmware/efivars.c +++ b/drivers/firmware/efivars.c @@ -793,6 +793,7 @@ static ssize_t efivarfs_file_write(struct file *file, spin_unlock(&efivars->lock); efivar_unregister(var); drop_nlink(inode); + d_delete(file->f_dentry); dput(file->f_dentry); } else { -- cgit v1.2.3