diff options
authorVladimir Zapolskiy <vladimir@tuxera.com>2020-10-10 21:25:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-10 15:52:54 -0700
commit64b7f674c292207624b3d788eda2dde3dc1415df (patch)
parent033b5d77551167f8c24ca862ce83d3e0745f9245 (diff)
cifs: Fix incomplete memory allocation on setxattr path
On setxattr() syscall path due to an apprent typo the size of a dynamically allocated memory chunk for storing struct smb2_file_full_ea_info object is computed incorrectly, to be more precise the first addend is the size of a pointer instead of the wanted object size. Coincidentally it makes no difference on 64-bit platforms, however on 32-bit targets the following memcpy() writes 4 bytes of data outside of the dynamically allocated memory. ============================================================================= BUG kmalloc-16 (Not tainted): Redzone overwritten ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: 0x79e69a6f-0x9e5cdecf @offset=368. First byte 0x73 instead of 0xcc INFO: Slab 0xd36d2454 objects=85 used=51 fp=0xf7d0fc7a flags=0x35000201 INFO: Object 0x6f171df3 @offset=352 fp=0x00000000 Redzone 5d4ff02d: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ Object 6f171df3: 00 00 00 00 00 05 06 00 73 6e 72 75 62 00 66 69 ........snrub.fi Redzone 79e69a6f: 73 68 32 0a sh2. Padding 56254d82: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ CPU: 0 PID: 8196 Comm: attr Tainted: G B 5.9.0-rc8+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 Call Trace: dump_stack+0x54/0x6e print_trailer+0x12c/0x134 check_bytes_and_report.cold+0x3e/0x69 check_object+0x18c/0x250 free_debug_processing+0xfe/0x230 __slab_free+0x1c0/0x300 kfree+0x1d3/0x220 smb2_set_ea+0x27d/0x540 cifs_xattr_set+0x57f/0x620 __vfs_setxattr+0x4e/0x60 __vfs_setxattr_noperm+0x4e/0x100 __vfs_setxattr_locked+0xae/0xd0 vfs_setxattr+0x4e/0xe0 setxattr+0x12c/0x1a0 path_setxattr+0xa4/0xc0 __ia32_sys_lsetxattr+0x1d/0x20 __do_fast_syscall_32+0x40/0x70 do_fast_syscall_32+0x29/0x60 do_SYSENTER_32+0x15/0x20 entry_SYSENTER_32+0x9f/0xf2 Fixes: 5517554e4313 ("cifs: Add support for writing attributes on SMB2+") Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 32f90dc82c84..d44df8f95bcd 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1208,7 +1208,7 @@ smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon,
rqst[1].rq_iov = si_iov;
rqst[1].rq_nvec = 1;
- len = sizeof(ea) + ea_name_len + ea_value_len + 1;
+ len = sizeof(*ea) + ea_name_len + ea_value_len + 1;
ea = kzalloc(len, GFP_KERNEL);
if (ea == NULL) {
rc = -ENOMEM;